Glossary

abonné A season ticket subscriber, in this case at the ballet or opera.
abrasion A loss of surface material due to rubbing, scraping, frequent touching, or inexpert solvent cleaning.
age cracks The formation of cracks that occur due to a loss of elasticity in the paint film and priming as these materials age, combined with responses to environmental changes (i.e. expansion and contraction of the support).
ancien régime The period in French history from about 1650 to 1789 (before the French Revolution). It was characterized by a divine-right absolute monarchy, a society based upon privileges for the rich and well-connected, and the Catholic Church as the religious establishment. The monarchy fell on August 10, 1792, after months of royal intransigence, and the Revolution entered a new more radical phase. King Louis XVI was executed in January 1793.
armature An unseen skeleton or framework, typically made of wood or metal, used to support a figure modeled in a soft plastic material, such as wax or clay.
artist supplier(s) Also called colormen and color merchants. Artist suppliers prepared materials for artists. This tradition dates back to the Medieval period, but the industrialization of the nineteenth century increased their commerce. It was during this time that ready-made paints in tubes, commercially prepared canvases, and standard-format supports were available to artists for sale through these suppliers. It is sometimes possible to identify the supplier from stamps or labels found on the reverse of the artwork (see canvas stamp).
atmospheric perspective An artistic technique used to create the illusion of depth in a composition in which distant elements are cooler and more diffuse, causing them to recede.
aureole Light encircling the head or body of a sacred figure.
baccalauréat A national examination taken when French students complete their secondary education, generally between the ages of fifteen and eighteen. It is the required qualification in France for anyone wishing to continue studies at the university level.
bachot A small flat-bottomwed boat used to cross rivers and reconizable for its lifting front, which facilitates standing on the bank.
bag wig An eighteenth-century wig with hair that is tied in back and contained in a small silk sack or cloth bag.
ballast(s) Any heavy material, such as gravel, sand, metal, or water, placed in the hold of a ship to weigh it down in the water and prevent it from capsizing when under sail or in motion.
Barbizon School A group of French artists, who united around 1830 to form the Barbizon School, which was named after a small village thirty miles northwest of Paris, where they lived and painted. Rebelling against the French Academy’s refined, idealized landscapes, these artists infused the immediacy of the sketches they created outdoors into their finished studio paintings.
Belle Époque A period coinciding with the end of the Second Empire (1852–1870) in France, and the outbreak of the First World War (1914), characterized by optimism, economic prosperity, technological and scientific progress, and decadence. See also Second Empire.
Bengal lights A firework or flare with a steady blue light, used, especially formerly, as a signal.
blanching A whitish haze or discoloration that may indicate deterioration of a varnish layer or an alteration of the paint film caused by inappropriate cleaning.
boom A spar extending from a mast to hold the bottom of a sail outstretched.
bowsprit A large spar or boom running out from the stem of a vessel, to which the foremast stays (ropes) are fastened.
brilliants A gemstone cut with many facets to catch the light so as to shine brilliantly.
cabinet A room designated for an art collection, usually drawings, prints, or objets d’art
cabochon A gemstone that has been polished, usually into a rounded shape, but not faceted.
canvas stamp An ink stamp, often present on the reverse of the canvas, signifying the company that sold or prepared the canvas. As these companies sometimes performed framing and restorations, these stamps could also reflect these services.
carte-de-visite French for “calling card.” A small card bearing a photographic portrait, which a sitter exchanged with family and friends. Cartes-de-visites were very popular in Europe and the United States in the mid-nineteenth century.
cartoon A full-scale drawing on paper, often executed with chalk or charcoal, which is used to transfer a design to another support.
caryatid In classical architecture, a stone carving of a draped female figure used instead of a column as a support.
catalogue raisonné A thorough, reasoned and systematic documentation of all works by an artist or all works in a given medium (such as painting, sculpture, works on paper) known to and accepted by the author(s) at the time the catalogue is prepared.
centaur In Greek mythology, a race of half-human, half-horse creatures.
centerboard(s) A retractable board or plate, situated in the midline of the hull of a sailing vessel, that may be lowered or raised to vary the vessel’s lateral resistance and drag or raised for navigation in shallow water.
chemise A plain, thin white cotton garment with short sleeves and sometimes a low neckline.
chiaroscuro Italian for “light-dark.” A technique used in two-dimensional art to add high contrast between lighted and shadowed areas and to emphasize their three dimensionality.
Cloisonnism A style of painting associated with some of the painters who worked at Pont-Aven in Brittany in the 1880s and 1890s. It is characterized by flat forms of bold colors separated by dark outlines. The term is derived from cloisonné, a kind of decorative enamelwork.
cognate In monotypes, cognates are multiple prints pulled from an inked image on a plate. The first print is usually the strongest, and the image quality reduces with each subsequent pull. It is usually possible to pull only two or three prints before the image becomes unreadable. See also monotype.
Comédie-Italienne The French term for Italian commedia dell’arte companies who performed in France. Coined in 1680, it was intended to distinguish Italian plays from native French plays. The Comédie-Italianne was expelled from Paris in 1697 but permitted to return in 1716. See commedia dell’arte.
commedia dell’arte Italian for “comedy of professional artists.” A theatrical form involving improvisation and a cast of stock characters that emerged in northern Italy in 1545 and rapidly gained popularity throughout Europe. Its heyday was the sixteenth through eighteenth centuries.
Communards A member or supporter of the Paris Commune of 1871. See “Paris Commune.”
commune In France and French-speaking countries, a commune is a small administrative division governed by a mayor and municipal council.
compressed charcoal A dry drawing material composed of charcoal, ground to a powder, and formed into a stick with aid of a small amount of a non-waxy and non-oily binder. The line created by compressed charcoal is characterized by a firm and dense appearance.
contrapposto Italian for “counterpoise.” A term used in the visual arts to describe a figure standing with their weight on one straightened leg while the other leg is more relaxed. The posture shifts the hips and the shoulders in opposite axes.
Council of Trent A council of the Roman Catholic Church, held in in the city of Trent, Italy, in three parts from 1545 to 1563, that responded to the doctrinal challenges of the Protestants. It played a key part in the Counter-Reformation and played a vital role in revitalizing the Roman Catholic Church in many parts of Europe. See also Counter-Reformation.
counterproof (pastel) Pastel paintings can be counterproofed by dampening either the original image or a fresh sheet of paper, and running both through a printing press. The resulting image would be reversed and both images would be lighter in tone.
Counter-Reformation A period lasting about one hundred years from about 1545 (the opening of the Council of Trent) to 1648 (the end of the Thirty Years’ War), when the Roman Catholic church responded to doctrinal challenges from the Protestant Reformation and revitalized its own spirituality and morality. See also Council of Trent.
contrapposto Italian for “counterpoise.” A term used in the visual arts to describe a figure standing with their weight on one straightened leg while the other leg is more relaxed. The posture shifts the hips and the shoulders in opposite axes.
cradle A grid-like wooden structure attached to the reverse of a panel by a restorer to prevent warping.
craquelure The network or pattern of cracks that develop on a paint surface as it ages.
crayon Traditionally, the French term crayon referred to a wide variety of fabricated, dry drawing media including ground and compressed chalks and pastels. For the purposes of this catalogue, crayon refers to a drawing medium where pigments, dyes, or a mixture of the two are mixed with wax, grease, or oils, or any combination of the three, and compressed into a stick.
croquetons Georges Seurat’s term, derived from the French word croquis (sketch), for his small oil sketches on panel. They were easily transported, making them ideal for painting outdoors.
cuirass The breastplate and back plate of armor, which are fastened together.
cusping A scalloped pattern along the canvas edges that relates to how the canvas was stretched. Primary cusping reveals where tacks secured the canvas to the support while the ground layer was applied. Secondary cusping can form when a pre-primed canvas is re-stretched by the artist prior to painting.
Damascened steel A steel of legendary sharpness and strength, whose method of forging has been lost to time. This type of steel shows complex patterns on the surface, which are the result of the unique forging methods used for its creation. Its name comes from a perceived resemblance to the rich tapestry patterns of damask silk.
dark-field monotype A subtractive image creation process where the printing matrix (the nonporous surface onto which the ink is applied) is entirely covered with ink, and the design is created by removing the ink. See also monotype.
deckle edge The edge of a paper sheet that is formed by pulp caught between the deckle, metal or wooden frame, and the papermaking screen. The deckle edge typically has less fiber than the remainder of the sheet and is characterized by a lacy appearance.
delamination The separation of layers in a painting. Examples include separation of the original canvas from the lining canvas, or separation of the paint layer from the ground layer.
dériveur sailboat equipped with a centerboard.
dinghy A small boat carried on board, or towed behind, a larger vessel.
disc floret Any of the small, tubular flowers at the center of certain composite plants, such as the daisy.
drying cracks Also known as traction cracks, these are formed as the paint dries. They are usually the result of a "lean" paint with a small percentage of oil drying faster than an underlying "fat" paint layer with a higher percentage of oil. The quick drying of the top layer causes the paint layer to shrink and crack.
drying oil Drying oils are oils which have the property of forming a solid, elastic substance when exposed to the air. Drying oils that commonly occur in oil paints are linseed, walnut, and poppyseed.
ébauche The first applications of paint that begin to block in color and loosely define the compositional elements. Also called underpainting.
effets French for “effects.” An artist’s emphasis on the atmospheric effects of time and weather on the subject matter.
electron-beam-excited X-ray spectrometry (sometimes referred to as XES for “X-ray energy spectrometry” or EDX for “energy-dispersive X-ray spectrometry”) An analytical technique used for the identification of elements without regard to their state of combination. The underlying principle of X-ray spectrometry is the same as that of X-ray fluorescence spectroscopy (XRF): individual elements can be induced to emit unique identifying X-rays. When used during examination of a sample in the scanning electron microscope (SEM), it offers several profound advantages over in-situ analysis with the handheld unit or XRF elemental mapping spectrometer. Electron beam excitation in the SEM favors the response of light elements including even carbon and oxygen. Also, the extreme localization of the electron beam exciting the response allows individual pigment particles to be analyzed in complicated mixtures while simultaneously revealing particle shapes. For example, the presence of both lead and chromium in a single rod-like particle differentiates it as chrome yellow from the case of viridian merely mixed with lead white, where chromium (oxide) and lead (carbonate) occur in separate particles.
en plein air (adjective: plein-air) French for “outdoors.” The term is used to describe the act of painting quickly outside rather than in a studio.
en pointe A term used in ballet to mean “on the tips of the toes.”
etching An intaglio printmaking technique where lines are etched with acid into a metal printing plate. The printing plate is covered with an acid resistant ground, and the artist draws a design into the ground with an etcher’s needle (a sharply pointed stylus). The plate is then immersed in an acid bath, and the metal exposed by the needle is eaten away. After removal of the ground, the plate can be printed by rubbing ink into the etched lines and running the plate and printing paper through an intaglio press.
facing A temporary measure in which a thin paper or tissue is adhered to the paint film to hold unstable paint in place. Adhesives can be water-soluble or solvent-based, depending on what is needed to safely remove the facing from the paint surface.
facture The artist’s characteristic handling of paint.
faulds Plate armor worn below a breastplate to protect the waist and hips.
Fauve French for “wild beasts.” A term coined in 1905 by the conservative art critic Louis Vauxcelles (1870–1943) to mock Henri Matisse (1869–1954), André Derain (1880–1954), and other artists who exhibited at the Salon d’Automne that year. Vauxcelles objected to these artists’ bold, non-naturalistic colors, which were sometimes applied onto the canvas straight from the paint tube, and their simplified, unsystematically rendered forms, which gave their paintings an almost abstract appearance. The Fauves’ use of vibrant colors to communicate emotional states inspired artists associated with Expressionism and other twentieth-century avant-garde movements.
fédérés French term for the troops who fought in support of the Paris Commune of 1871. See Paris Commune.
fermier général French for “general farmer.” A private citizen who collects taxes on behalf of the French monarchy.
fêtes galantes French for “gallant parties.” Paintings that feature elite groups of upper-class men and women shown in conversation, role playing, dancing, or flirting outdoors.
fiacre A small four-wheeled carriage for public hire named after the Hôtel de St. Fiacre in Paris, where such vehicles were first hired out.
fichu French for “thrown over.” A small triangular shawl, worn around a woman’s shoulders and neck.
fill material A material added to a loss of paint and/or ground to create an area level with the surrounding original paint.
fillet In picture framing, a fillet is a thin, decorative molding, usually made of wood, that separates the other parts of the frame from the artwork. It is often offset from the frame by a mat or similar flat element.
First French Empire A period lasting from 1804 until 1815, during which Napoleon Bonaparte crowned himself and his wife Josephine Emperor and Empress of the French and continued a series of wars, known as the Napoleonic Wars (1799–1815), to expand France’s territory. After his first forced abdication in April 1814, Napoleon was exiled to the island of Elba, from where he escaped. For one hundred days (March 20–June 28, 1815), Napoleon attempted to restore his power, but he was defeated by a coalition led by the Duke of Wellington and Marshal Blücher in the battle of Waterloo (June 18, 1815). Napoleon abdicated again on July 7, which marks the end of the first French Empire, and he died in exile on the island of Saint Helena in 1821.
fixative An adhesive or varnish that is applied to the surface of powdery media (pastel, chalk, charcoal, or graphite pencil) to prevent smudging or smearing. Fixatives may be applied during the composition process, so that new layers of media can be added without disturbing the underlayers, or after the artwork is complete. Historic fixatives include natural resins, vegetable gums or starches, animal or fish glues, casein, egg white, and a variety of other materials. In the nineteenth century, cellulose nitrate and other early synthetic polymers were available, and in the twentieth century, acrylics and polyvinyl co-polymers were included in fixative solutions. Until the early twentieth century, when methods for containing pressurized gasses were developed and disposable spray cans became common, the fixative could be spattered over the paper with a brush or applied with an atomizer (also called a blow-pipe or mouth sprayer).
flâneur French for “stroller”, “lounger”, “saunterer”, or “loafer.” A term popularized by writer Charles Baudelaire to describe a kind of urban male observer.
foldover edge The point at which the canvas begins to wrap around the stretcher, at the junction between the picture plane and tacking margin. See also turnover edge.
fore-and-aft From the bow to the stern; lengthwise.
founder One who casts metal, or makes articles of cast metal.
Fourier-transform infrared spectroscopy (FTIR) A broadly applicable microanalysis method for the identification of paint media classes such as oils, polysaccharides (gum arabic, etc.), proteins (glue and casein tempera), waxes (medium additions and restoration treatments), resins (varnish components), and synthetic media (restoration acrylics). FTIR is also very important for identifying pigments and fillers, and for differentiating closely-related compounds (e.g. neutral and basic lead carbonates, both of which may be found in lead white).
Franco-Prussian War The war of 1870–1871 between France (under Napoleon III) and Prussia, in which Prussian troops advanced into France and decisively defeated the French at Sedan. The defeat marked the end of the French Second Empire. For Prussia, the proclamation of the new German Empire at Versailles was the climax of Bismarck’s ambitions to unite Germany.
friable When paint is no longer sufficiently bound. Friable paint often appears powdery or crumbles easily.
frogging Ornamental braid or coat fastenings with spindle-shaped buttons and loops.
furnish in paper making, furnish refers to the fibers that compose the paper as well as to the mixture of fibers and water that eventually form the paper sheet.
genre Figural scenes of ordinary people engaged in the activities of everyday life.
Gilded Age A period in United States history from about 1870 to 1900 characterized by corrupt politicians and great financial gain through monopolies on industrial production. Although wages of industrial and skilled workers rose, the greatest wealth was collected by the entrepreneurs variously called “captains of industry” or “robber barons.” The new influx of wealth contributed to gross materialism.
glaze A transparent, oil or resin-rich paint application that influences the tonality of the underlying paint.
gouache A term originating in eighteenth century France, which, historically, refers to an opaque paint consisting of colored pigments or dyes, a white opacifying pigment, and a polysaccharide binder, usually gum arabic. Traditional gouache recipes sometimes include honey as a humectant. Although twentieth century and twenty-first century gouache paints are often visually indistinguishable from historic gouache paints, modern gouache paints include a variety of additives that produce a reliably uniform paint in terms of tint and handling properties.
Grand Manner An artistic style, popular in seventeenth and eighteenth-century England and France, that incorporated the influences of ancient Greek and Roman (classical) art, Italian Renaissance painters (such as Raphael, 1483–1520), and seventeenth-century Flemish portraitists (like Sir Anthony Van Dyck, 1599–1641, and Peter Paul Rubens, 1577–1640) to create an idealized rather than realistic approach to history painting and portraiture.
Grand Tour An extended tour of Europe, in particular Italy, in the 18th century, taken by wealthy young men (and some women), especially British and American ones, to complete their education and cultivation.
ground layer An opaque preparatory layer applied to the support, either commercially or by the artist, to prevent absorption of the paint into the canvas or panel. See also priming layer.
half basket weave A plain weave produced by double yarns in one direction and a single yarn in the other.
Haussmann, Baron Georges-Eugène Haussmann (1809–1891), known as Baron Haussmann, was a civil servant who spearheaded a massive urban renewal scheme in Paris during his tenure as Prefect of the Seine (1853–1870). His efforts to modernize the city were dubbed “Haussmannization.”
haute bourgeoisie French for ”the upper middle class“
Hauts-de-Seine A department in the Île-de-France region comprising Paris’s western suburbs.
hide glue Also called animal skin glue, hide glue is an adhesive produced by boiling the skin, bones, tendons, and other connective tissues of animals to extract collagen proteins.
hors catalogue Exhibited but not included in the catalogue.
hôtel particulier A grand, urban mansion for a private citizen that does not share party walls with residences nearby.
Huguenots A name for French Protestants in the 1500s to 1700s. France had been a mostly Catholic country until French Protestants emerged around 1517, and this led to a series of civil wars from 1562 to 1598, called the Wars of Religion. In 1598, the former-Protestant king, Henry IV, issued the Edict of Nantes to offer religious equality and tolerance to the Huguenots. Many years later, Henry’s grandson Louis XIV felt his absolute monarchy was threatened by the Huguenots’ growing religious minority, and in 1685 he revoked the Edict of Nantes. Protestants faced increased persecution, deportation, or massacres, and about 200,000 fled France to settle in non-Catholic Europe. See also Protestant Reformation.
hull(s) The body or frame of a ship, apart from the masts, sails, and rigging.
Hundred Years’ War The intermittent war between England and France from 1337 to 1453, arising out of the claim of the English kings to the French crown.
impact cracks A characteristic crack pattern that forms after a blow to a painting. When these appear as circular, spiral, or spider web-like, they are sometimes called sigmoid cracks.
impasto A thick application of paint, often creating texture such as peaks and ridges.
imprimatura A thin layer of paint applied over the ground layer to establish an overall tonality.
infrared (IR) photography A form of infrared imaging that employs the part of the spectrum just beyond the red color to which the human eye is sensitive. This wavelength region, typically between 700-1,000 nanometers, is accessible to commonly available digital cameras if they are modified by removal of an IR blocking filter that is required to render images as the eye sees them. The camera is made selective for the infrared by then blocking the visible light. The resulting image is called a reflected infrared digital photograph. Its value as a painting examination tool derives from the tendency for paint to be more transparent at these longer wavelengths, thereby non-invasively revealing pentimenti, inscriptions, underdrawing lines, and early stages in the execution of a work. The technique has been used extensively for more than a half-century and was formerly accomplished with infrared film.
infrared reflectogram An infrared image captured with an electronic infrared imager, typically in the 1000-2500 nanometer range. See Infrared reflectography (IRR).
infrared reflectography (IRR) A form of infrared imaging that exploits the behavior of painting materials at wavelengths beyond those accessible to infrared photography. These advantages sometimes include a continuing increase in the transparency of pigments beyond wavelengths accessible to infrared photography (i.e, beyond 1,000 nanometers), rendering underdrawing more clearly. The resulting image is called an infrared reflectogram. Devices that came into common use in the 1980s such as the infrared vidicon effectively revealed these features but suffered from lack of sharpness and uneven response. Vidicons continue to be used out to 2,200 nanometers but several newer pixelated detectors including indium gallium arsenide and indium antimonide array detectors offer improvements. All of these devices are optimally used with filters constraining their response to those parts of the infrared spectrum that reveal the most within the constraints of the palette used for a given painting. They can be used for transmitted light imaging as well as in reflection.
inner bailey The defensive wall surrounding a medieval castle’s inner court. The keep was usually located within this enclosure.
Intimisme French for “Intimism.” A stylistic term used to describe the work of late-nineteenth and early-twentieth-century artists such as Pierre Bonnard (1867–1947) and Edouard Vuillard (1868–1940), who painted domestic scenes with objects and people obscured by a mystical and highly suggestive ambiguity. Containing surface patterning and other decorative elements, these artists’ closely cropped and sometimes claustrophobic compositions offer fleeting views of psychologically charged spaces with palpable atmospheres.
jib A triangular sail secured to a stay (rope) forward of the mast or foremast.
Juliet balcony A shallow balcony fitted to the outside of a building in front of full-length windows or French doors.
keep The strongest and innermost tower of a medieval castle, serving as its last defense; also known as a donjon.
laid paper One of the two types of paper. Laid papers are machine or handmade papers, formed on a screen with parallel and tightly spaced wires that form "laid lines" which are visible on the sheet. The laid wires are held together by more widely spaced wires called "chain" lines. In handmade papermaking, the chain wires also secured the screen to the ribs of a wooden frame (the frame and wire assembly is referred to as a mold) that was dipped into a vat of paper-making fibers. In the late eighteenth century, there were widespread changes in the laid mold structure, and papers produced prior to this time are distinguishable by an accumulation of fibers along the chain lines. The other type of paper is wove paper.
lapis lazuli A rock containing several minerals, including the brilliant blue lazurite, along with calcite, diopside, and iron pyrite, among others. Obtained by trade along the Silk Route, natural ultramarine was produced by a laborious and costly process of grinding and separating the blue lazurite from the unwanted minerals. The intensity of its color depends on not being ground too finely while freeing it of colorless matter, two objectives that were difficult to meet simultaneously, resulting different grades. A means of making synthetic ultramarine was discovered in the 19th century, making it cheaply available in large quantities and virtually eliminating demand for the natural variety.
lead white The most widely used white pigment from Roman times until well into the industrial period, it consists of cerussite and/or hydrocerussite, mineral names for neutral lead carbonate and basic lead carbonate, respectively. Plumbonacrite, another basic lead carbonate with proportionately less carbonate than hydrocerussite, can sometimes be found, as well. The whitest forms used in painting were historically produced by inducing lead metal to corrode in the presence of vinegar fumes.
linear perspective A technique in which an artist uses lines to help create the illusion of depth or distance on a two-dimensional picture plane, with objects in the foreground appearing large and objects in the background appearing small.
lining A procedure used to reinforce a weakened canvas that involves adhering a second fabric support using adhesive, most often a glue-paste mixture, wax, or synthetic adhesive.
linocut A relief printmaking technique characterized by supple lines and flat areas of color. Using a sharp knife, V-shaped chisel, or similar implement, a design is cut into or gouged from a sheet of linoleum, which is softer and easier to carve than wood. The raised, uncarved surface is then inked with a brayer (roller) and impressed onto a paper or fabric support. The resulting composition is a negative image in reverse of the carved design. Introduced in the 1890s, linocuts became increasingly popular in the twentieth century.
lithography Invented by Alois Senefelder (German, 1771–1834) in the late eighteenth century, lithography is a planographic printmaking technique. The name (literally: stone drawing) comes from the use of a stone as the printing matrix; however, grained aluminum and metal plates are also used. Preparation and printing of the images is a based on the hydrophobic nature of grease. The design is drawn with greasy crayons or an oily ink called tusche. The stone is then synthesized so that printing can be accomplished by first wetting the stone (the water is repelled by the grease in the media) and then inking the stone with a greasy ink (the ink adheres grease in the crayon and tusche). The image is transferred to the paper with a press that exerts tremendous pressure on the stone. Like other printing techniques the printed image reverses the image on the stone. There is no platemark as seen in monotypes; instead the area of contact between the stone and the paper will have a flatter appearance than the surrounding paper.
livre de raison A chronological inventory of an artist’s completed works, either verbal or visual in nature.
lost-wax process A method of casting that involves making a model with a wax surface, enclosing the model in a mold, melting the wax out, and pouring molten metal between the core and mold. Also known by its French name, cire perdue.
lozenged Ornamented with diamond shapes of alternate colors.
macrophotogrammetry A process of recording measurements through multiple, overlapping photographs captured from different angles of an artwork. The photographs are mathematically combined to create a three-dimensional model of the object or its surface.
mainsail The principal sail of a ship.
mansard roof A roof with two slopes on all sides, where the lower slope is steeper than the upper one.
Marais A historic neighborhood in the third and fourth arrondissements of Paris.
marchande de modes A vendor who supplied women’s fashion accessories, such as trimmings to decorate caps and shawls.
marine Term used to describe a variety of painted sea subjects, including beach scenes, vistas of the open sea, and shipwrecks or portraits of ships.
marouflage A technique in which canvas is pasted to a wall as a base for mural painting, traditionally using an adhesive made of white lead ground in oil.
mechanical cracks Cracks, either localized or overall, that form in response to movement or stress.
mineral species A non-living, homogeneous substance found in nature, classified by the proportions of the elements that it contains and the arrangement of those elements in a crystal lattice. When determined to be a singular entity, or phase, as opposed to a mixture of different entities, it is given an internationally agreed-upon species name (often ending in -ite). Pigments and alteration products of artist’s materials that form with the same composition and structure as their natural analogs are often identified by the mineral species name. Substances with widely varying compositions that do not take on a crystalline structure are often glasses, a state of matter that accommodates a higher degree of randomness in the linkages between its atoms.
moiré silk A French word “moiré,” derived from “moirer,” meaning to water. Originally, it described a wavy texture on silk resembling water’s effect on sand. Despite this association, water was not employed in its production. Instead, steam-filled rollers emboss the surface of the cloth with high pressure, creating an organic, non-repetitive pattern.
monotype A type of planographic print where a design is drawn or painted on a non-porous surface, such as a printing plate or glass, and the design is transferred, in reverse, to paper by manual pressure, or pressure from a printing press. The monotype process produces unique prints because the ink is depleted each time paper comes in contact with the matrix. The first print is the strongest in terms of tone and contrast, and the quality decreases with each subsequent print. (See also dark-field monotype and cognate).
Nabis Nabi is the Hebrew word for prophet. Founded by Paul Sérusier, the Nabis were a group of Post-Impressionist painters active in France from 1888 to around 1900. Utilizing a simplified style of thick, undulating contours and flat planes of vibrant color inspired by Synthetism, the Nabis rejected naturalistic depictions of reality and relied instead on metaphor and purely formal devices to evoke feelings and subject matter. An experimental group of painters, the Nabi created stage sets for Symbolist theatre productions and painted on unconventional supports such as velvet and cardboard. See also Synthetism.
Neo-Impressionism A term coined in 1886 by French art critic Félix Fénéon to describe a style of painting pioneered by Georges Seurat. He and his followers espoused a scientific approach to color and a painting technique known as pointillism.
noir French for “black.” Redon’s term for the predominately black drawings and lithographs that he produced between 1870 and 1890. The artist was fascinated with darkness, and his noirs often depict shadowy realms, spiritual beings, and mysterious creatures. They also display painterly qualities and exploit drawing materials and printmaking processes that developed during the Industrial Revolution.
Norwegian A solid boat for walking and angling. It is a canoe with a very elegant rounded lift often seen in other Impressionist paintings.
Opportunist The Opportunist Republicans were a center-left faction of the French Republican party during the late nineteenth century.
Orientalist An art-historical term for subject matter depicting the Near East by western artists, primarily in the nineteenth century.
overpaint Restoration paint that covers original paint that may or may not be damaged. Historically, overpaint has often been applied too broadly, altering the intended aesthetic of the painting and sometimes introducing conceptions foreign to the original artist, thereby altering our understanding of the work and the era to which it belongs.
Paris Commune An insurrectionary socialist government in Paris that lasted from March 18 to May 27, 1871.
Passion of Christ The sequence of events encompassing Jesus Christ’s triumphal entry into Jerusalem, his suffering, death, and ultimately his resurrection.
pastel A type of drawing stick made from finely ground pigments or other colorants (dyes), fillers (often ground chalk), and a small amount of a polysaccharide binder (gum arabic or gum tragacanth). While many artists made their own pastels, during the nineteenth century, pastels were sold as sticks, pointed sticks encased in tightly wound paper wrappers, or as wood encased pencils. Pastels can be applied dry, dampened, or wet, and they can be manipulated with a variety of tools including paper stumps, chamois cloth, brushes, or fingers. Pastel can also be ground and applied as a powder, or mixed with water to form a paste. Pastel is a friable media, meaning that it is powdery or crumbles easily. To overcome this difficulty, artists have used a variety of fixatives to prevent image loss.
pastorals A genre of painting that portrays rural life, especially the lives of shepherds, in an idealizing way. Such works represent the courtier’s or city-dweller’s dream of escape.
pauldrons Plate armor that covers one’s shoulders.
peinture à l’essence De-oiled paint. Peinture à l’essence was produced by the artist by leaching much of the linseed oil out of commercial paints and mixing the resulting thickened paint with turpentine. The resulting paint could be applied as a wash and dried more quickly than unmodified paint.
pendant One of two paintings conceived as a pair and intended to be displayed togther.
pentimento (pl: pentimenti) A change to the composition made by the artist that is visible on the paint surface. Often with time, pentimenti become more visible as the upper layers of paint become more transparent with age. Italian for "repentance" or "a change of mind."
photomicrograph An image captured using a microscope.
picture plane The two-dimensional surface where the artist applies paint.
picture space The whole area of a painting, considered in relation to its parts.
piedouche Small pedestal that serves as a support for a bust, vase, or statue.
plain weave A basic textile weave in which one weft thread alternates over and under the warp threads. Often this structure consists of one thread in each direction, but threads can be doubled (basket weave) or tripled to create more complex plain weave. Plain weave is sometimes called tabby weave.
plastilene A sulfur-rich, non-drying modeling clay invented in the late nineteenth century and still in use today.
platemark A depression in a sheet of paper caused by the edge of a printing plate. The platemark is the product of the pressure exerted by the printing press onto both the plate and the paper.
pointillism A technique of painting using tiny dots of pure colors, which when seen from a distance are blended by the viewer’s eye. It was developed by French Neo-Impressionist painters in the mid-1880s as a means of producing luminous effects.
polarized light microscopy (PLM) A method used for the study and differentiation of pigments based on the optical properties of individual particles, including color, refractive index, birefringence, etc. PLM is particularly useful in identifying the presence of organic pigments such as indigo and Prussian blue, which often cannot be differentiated from paint medium in the scanning electron microscopy (SEM); differentiating synthetic pigments from their natural analogs by particle shape or the presence of extraneous mineral matter; and disclosing the presence of pigments with similar composition but differing color, such as red and yellow iron oxides.
polyvinyl acetate A thermoplastic resin created by polymerizing vinyl acetate. White in color and tacky when wet, it dries to form a clear, tough film. Polyvinyl acetate is used widely in emulsions for paints and adhesives. Also noted as PVAc, PVAC, or (less inaccurately) as PVA.
priming layer An opaque preparatory layer applied to the support, either commercially or by the artist, to prevent absorption of the paint into the canvas or panel. See also ground layer.
profil perdu French for "lost profile." The artist shows their subject without the profile of the head being visible. A profile of a human head that is not seen directly from the side, but more from the back of the head.
Protestant Reformation A movement in Western Europe that began in 1517, when Martin Luther posted his Ninety-five Theses on the door of the Castle Church in Wittenberg, Germany. The movement called for the reform of the Roman Catholic Church, which had far-reaching political, economic, and social effects. It led to the reformulation of certain basic tenets of Christian belief and resulted in the division of Western Christendom between Roman Catholicism and the new Reformed and Protestant Churches. Calvinism also developed from the Reformation. It was named for John Calvin, who released the first edition of his Institutes of the Christian Religion in 1536.
Purkinje effect Discovered by Czechoslovakian physiologist and anatomist Johannes Evangelist Purkinje (1787–1869), the Purkinje effect relates to the human eye’s greater sensitivity to the blue and blue-green region of the visible light spectrum in low light level situations. At very low light levels, when the human eye can no longer see color, lighter blues and greens will appear lighter than reds and oranges of the same value.
putto (plural: putti) A representation of a naked child, especially a cherub or a cupid in Renaissance art.
quartier The city of Paris is divided into twenty arrondissements, or districts, each of which comprises four quartiers.
quay A man-made bank or landing stage, usually built parallel to the shoreline, for loading and unloading ships.
raking light An examination technique in which light is placed at a shallow angle from one direction to reveal the surface topography.
Raman spectroscopy A microanalytical technique applicable primarily to pigments and minerals, differentiating them based on both chemical bonding and crystal structure, often with extremely high sensitivity for individual particles. For example, traditional indigo and synthetic phthalocyanine blue are both carbon compounds not well differentiated by other methods utilized here, especially when used dilutely. However, they give unique Raman spectra. Calcium carbonates derived from chalk or pulverized oyster shell of identical chemical compositions can be differentiated based on their crystal structures (calcite and aragonite, respectively).
ray floret Any of the strap-shaped flowers that extend like petals from the center of certain composite plants, such as the daisy.
rebate (or rabbet) A groove on the inside of a frame to hold the glass (glazing), mount, and artwork.
reflected infrared digital photograph An infrared image produced in the 700–1000 nanometer range, typically captured using an infrared-modified digital camera. See infrared photography.
reflected light microscopy (of cross-sections) A procedure used in limited cases with microsamples to determine the layering of paint applications and thereby resolve pigments into successive layers of application. Samples are embedded in mounting resin under vacuum, cured at 60 degrees Celsius, ground, and polished to a one-micron finish. Thereafter they are examined using the reflected light microscope, ultraviolet fluorescence microscope, and scanning electron microscope.
Regency Part of the Georgian era in England, King George III’s son ruled as his proxy, dating from approximately 1811 until 1820.
Reign of Terror A period of the French Revolution that lasted from March 1793 until July 1794. The Revolutionary government, known as the Convention, executed the king, and then set about attacking and executing opponents and anyone else considered a threat to the regime. The Reign of Terror is associated with the Jacobin consolidation of power in the National Convention under their leader Maximilien Robespierre. It ended with his downfall and execution on 9-10 Thermidor (July 27) in the summer of 1794, although spurts of violence and executions continued throughout the Revolution.
repoussoir An object, motif, or figure placed on the right or left foreground of a painting used to direct the viewer’s eye into the composition and increase the illusion of depth.
reserve An area of the composition left unpainted with the intention of inserting a feature at a later stage in the painting process.
retouching Paint application by a conservator or restorer to cover losses and unify the original composition. Retouching is an aspect of conservation treatment that is aesthetic in nature and that differs from more limited procedures undertaken solely to stabilize original material. Sometimes referred to as inpainting or retouch.
Rococo Developed under the reign of Louis XV (r. 1715–1774) and his mistress the Marquise de Pompadour (1721–1764), the Rococo style featured sensual, pastoral, and mythological subjects set in silvery light and created in painterly, soft colors. The works of François Boucher epitomize the style that spread to every medium, including furniture and decorative arts.
Royal Academy of the Arts A London-based gallery and art school founded in 1768 by a group of artists and architects.
Salon, the Exhibitions organized by the French Royal Academy of Painting and Sculpture (Académie Royale de Peinture et de Sculpture) and its successor the Academy of Fine Arts (Académie des Beaux Arts), which took place in Paris from 1667 onward.
sandbagger(s) A sailboat that uses sandbags as ballast.
satyr In Greek mythology, a woodland god depicted as a man with a goat’s ears, tail, legs, and horns.
scanning electron microscopy (SEM) Performed on a microsample of paint, the SEM provides a means of studying particle shapes beyond the magnification limits of the light microscope. This becomes increasingly important with the painting materials introduced in the early modern era, which are finer and more diverse than traditional artists’ materials. The SEM is routinely used in conjunction with an X-ray spectrometer, so that elemental identifications can be made selectively on the same minute scale as the electron beam producing the images. SEM methods are particularly valuable in studying unstable pigments, adverse interactions between incompatible pigments, and interactions between pigments and surrounding paint medium, all of which can have profound effects on the appearance of a painting.
scumble A thin layer of opaque or semi-opaque paint that partially covers and modifies the underlying paint.
Second Empire The regime of Napoléon III in France, which lasted from 1852 to 1870.
sedimentary grain A mineral grain, or rock fragment containing several mineral grains, liberated by the weathering of solid rock formations. They are typically wear-rounded as they are carried by wind or water. Garden soil is generally comprised of sedimentary grains along with finer matter such as clay and organic matter. Earth pigments often contain sedimentary grains but some consist of minerals mined in-situ, where they formed.
selvedge The original woven edge of fabric formed by the weft threads looping over the warp during the loom weaving process. The selvedge runs the length of the fabric bolt, parallel to the warp threads, and forms a finished edge.
semaine sanglante The final week of the Paris Commune (May 21–28, 1871), during which the Versaillais (French troops) launched a major offensive to retake Paris and executed thousands of insurgents. See Paris Commune.
sgraffito (pl: sgraffiti) An Italian term meaning “scratched,” in which a compositional design or decoration is created using a sharp tool to scrape into the wet medium (paint, plaster, glaze, slip, etc) and reveal contrasting underlying layers.
simultaneous contrast Simultaneous contrast is the interaction of two colors when placed side by side. Depending on the colors, the viewer’s perception of the color will change. For example, blue will cause red to appear orange, and red causes blue to appear green. Complementary colors (colors that are opposite each other in a color wheel, such as red and green, blue and orange, or yellow and purple) produce the most striking simultaneous contrast. While simultaneous contrast was formulated by the French chemist Michel Eugène Chevreul (1786–1889) in his treatise The Principles of Harmony and Contrast of Colors, and Their Applications to the Arts (1839), the use of simultaneous contrast in painting predates the treatise by more than 100 years.
sizing layer A dilute glue layer, usually animal-based protein such as hide glue, applied to a canvas prior to the ground and paint layers. Its purpose is to shrink the canvas before use and to act as a sealant, protecting the canvas from degradation of acidic materials, such as oils. The glue material is often called size, while the process is called sizing.
sluice A wood or masonry structure for impounding the water of a river or canal, provided with an adjustable gate or gates by which the volume of water is regulated or controlled.
Société des Artistes Indépendants A group founded in 1884 in Paris by Odilon Redon, Albert Dubois-Pillet, Georges Seurat, and Paul Signac that created the Salon des Indépendants as an alternative to exhibiting at the Salon organized and juried by the French Royal Academy of Painting and Sculpture (Académie Royale de Peinture et de Sculpture). The Salon des Indépendants has no selection committee; instead, artists can exhibit on payment of a fee. The exhibitions became the main venue for many artists, particularly the Post-Impressionists in the late 19th century. The Salon des Indépendants is still in existence today. See also Salon, the.
sortie A sudden rushing forth of troops from a besieged position to attack the enemy.
sous-bois French for ”undergrowth“ A genre of paintings of the forest floor made popular by the Barbizon painters from the 1830s to about 1870.
spar Any pole, such as a mast, yard, boom, or gaff, supporting or extending a sail of a ship.
specular illumination An examination technique in which light is reflected off an artwork’s surface in order to better visualize sheen variation, surface textures, and surface anomalies.
spline pieces of wood that are inserted into a miter to add strength and stability to joint.
staffage Small figures or animals used to enliven a landscape or architectural painting.
standard-format supports Commercially prepared supports available through art suppliers, which gained popularity in the nineteenth century during the industrialization of art materials. Available in three formats figure (portrait), paysage (landscape), and marine (marine), these were numbered 1 through 120 to indicate their size. For each numbered size, marine and paysage had two options available: a larger format (haute) and smaller (basse) format.
stereographic photography Twin images that, when viewed together through a special device, produce an illusion of three-dimensionality.
stock A type of neckwear made of a band of fine, usually white linen, carefully pleated and stitched to fit closely over a man’s shirt collar.
strainer A wooden structure to which the painting’s canvas is attached. Unlike stretchers, strainers cannot be expanded.
stretcher A wooden structure to which the painting’s canvas is attached. Unlike strainers, stretchers can be expanded slightly at the joints to improve canvas tension and avoid sagging due to humidity changes or aging.
stretcher cracks Linear cracks or deformations in the painting’s surface that correspond to the inner edges of the underlying stretcher or strainer members.
strip lining A conservation technique used to strengthen/repair tacking margins that have weakened or failed. New fabric is adhered to the painting’s damaged tacking margins to allow the stretcher to exert its normal tensioning on the original canvas.
stumping Blending, removing, lightening, or softening stokes of powdery media (pastel, charcoal, chalk, or graphite pencil) with a stump or tortillon. The stump is made from paper, leather or thin felt, which is rolled so that it forms a point. If blending is the main object of stumping, then the technique is referred to as stump blending to differentiate between blending with fingers, a brush, or chamois skin.
sur le motif French for “in front of the object.” A term used for sketching or painting from life.
Synchrotron X-ray fluorescence spectrometry elemental mapping or synchrotron MA-XRF The synchrotron is essentially a vastly brighter and more localized source of X-rays substituted for an X-ray tube. A unique trait of the synchrotron, not shared with X-ray tube sources, is the ability to tune all of its X-ray energy to a single level at which absorption by an overlying lead layer is minimized, thereby partially overcoming the shielding effect of upper layers of paint. The Maia X-ray detector offers an array of 384 individual detector elements capable of simultaneously measuring the torrent of characteristic fluorescent X-rays produced by the pigments under illumination of the synchrotron source. These 384 components surround the synchrotron beam and collect the characteristic fluorescent X-rays of the pigments from each point on the painting as it is swept past the beam and detector.
Synthetism Rejecting the Impressionist’s naturalistic approach to depicting observed reality, Paul Gauguin, Emile Bernard, and other Post-Impressionist artists working in and around the Breton town of Pont-Aven in the late 1880s formulated a more symbolic style of representation called “synthétisme” (synthetism). Utilizing thickly painted contours and flat planes of vibrant color, synthetist artists hoped to register their subjective, aesthetic responses to subject matter with purely formal devices. First exhibiting their works in 1889, the “groupe synthétiste” was founded in 1891. Paul Sérusier, who was involved with Synthetism, was also the founder of the Nabis. See also Nabis.
tache French for “blot” or “stain.” An application of a single color of paint, quite thickly applied, using a bold, flat and even-loaded stroke.
tacked To change the course of a vessel by turning its bow into and across the wind; to maneuver a vessel against the wind by a series of tacks.
tacking edge The outer edges of canvas that wrap around and are attached to the stretcher or strainer with tacks or staples. See also tacking margin.
tacking margins The outer edges of canvas that wrap around and are attached to the stretcher or strainer with tacks or staples. See also tacking edge.
terre-neuvier The French term for a vessel used for cod fishing off the coast of Newfoundland.
tête d’expression French term for a study of the face intended to evoke a particular emotion or state of mind.
Third Republic The republic established in France in 1870, after the fall of Napoleon III, lasting until the German occupation of France in World War II.
Three Estates, the In pre-Revolutionary France (before 1789), society was divided into three classes. The First Estate was composed of the clergy and those who directed the Catholic church. They could impose a ten-percent tax (tithe). The Second Estate comprised the nobility and members of the Royal family, who did not have to pay taxes. The Third Estate encompassed the rest of society, upon whom all taxes fell, from the poorest people to the upper-middle classes.
thyrsus A staff or spear with an ornamental tip, such as a pinecone, that would be carried by Bacchic revelers.
topsail In a fore-and-aft rig, a square or triangular sail set above the gaff (a type of spar).
tortillon Also called a blending stump, the tortillon is a cylindrical blending tool for loose drawing media such as pastel, charcoal, chalk, and graphite pencil. Tortillons are traditionally made of rolled paper; however, at present, it is possible to purchase similar implements made of cast paper pulp. These are much easier to clean and have a longer lifetime than the traditional rolled paper tool.
towpath A path by the side of a canal or navigable river for use in towing.
traction A method of transportation for large stones or boulders in a river. The water rolls the stones along the river bottom since they are too heavy to be suspended in the water.
traction cracks Also known as drying cracks, these are formed as the paint dries. They are usually the result of a “lean” paint with a small percentage of oil drying faster than an underlying “fat” paint layer with a higher percentage of oil. The quick drying of the top layer causes the paint layer to shrink and crack.
transfer lithography Although transfer lithography was introduced in Alois Senefelder’s (German, 1771–1834) treatise on lithography in the late eighteenth century, it was not until the lithography revival of the late nineteenth century that the technique caught on. Transfer lithography involves drawing on a prepared paper with lithographic crayons and tusche (an oily ink). The paper is then laid face down on the stone, wetted with water and solvents such as turpentine, and passed through the press. The image transferred to the stone, and could be processed, inked, and printed. The resulting prints resembled the original drawing in orientation (the image was not reversed) and media application. The original drawing was usually destroyed during transfer process. See also lithography.
transmitted infrared (IR) photography An examination technique whereby the light source is placed on one side of the artwork while an electronic infrared imager or IR-modified digital camera placed on the opposite side captures the IR that is transmitted. This form of IR photography can be used to detect characteristics of the artist’s paint application, underlying compositions, artist changes, or inscriptions now covered by a lining canvas.
transmitted light An examination technique in which light is projected through the painting to examine the painting substrate or to reveal variations in paint application.
Treaty of the Pyrenees Signed in 1659, the treaty ended the hostilities between France and Spain and the Thirty Years’ War. It was sealed by the marriage of Louis XIV of France and Marie‐Thérèse, daughter of Philip IV of Spain.
tricorn A cocked hat with the brim turned up on three sides.
tronies Old Dutch for “faces.” Painted studies of the face or head of an anonymous sitter, sometimes in exotic costume, or featuring an exaggerated facial expression.
turnover edge The point at which the canvas begins to wrap around the stretcher, at the junction between the picture plane and tacking margin. See also foldover edge.
twill weave A canvas weave in which one weft thread passes over one or more warp threads before passing under two or more warp threads, creating a pronounced diagonal pattern.
uchiwa The uchiwa is a fan format that is thought to have originated in Japan. The uchiwa is a rigid fan that does not fold and is composed of a bamboo or wooden handle that is split, dampened, and spread out into thin ribs. These are often held in place or spaced out with two lines of string or thread that is woven around the ribs. The ribs are covered with paper, which is often painted or printed.
ukiyo-e Japanese for “pictures of the floating world.” Japanese woodblock prints created by woodblock cutters (sometimes following an artist’s brush drawing) that feature crisp contours and flattened space without much shadowing.
ultraviolet (UV) fluorescence or UV-induced visible fluorescence The reflected visible light produced when painting materials interact with ultraviolet (UV) radiation. Not all materials fluoresce, but the color and intensity of the fluorescence is frequently used to differentiate between original and restoration materials, characterize the varnish layers, or reveal the distribution of pigments across the composition.
Ultraviolet (UV)-induced visible light fluorescence microscopy (of cross sections) A method used in limited cases with microsamples to determine the layering of paint applications. Differences in both pigmentation and formulation of the paint medium will influence the UV fluorescence behavior of the paint layers.
ultraviolet (UV) radiation A segment of the electromagnetic spectrum, just beyond the sensitivity of the human eye, with wavelengths ranging from 100–400 nanometers. For a description of its use in the study of art objects, see ultraviolet (UV) fluorescence or UV-induced visible fluorescence.
underdrawing A drawn or painted sketch beneath the paint layer. The underdrawing can be made from dry materials, such as graphite or charcoal, or wet materials, such as ink or paint.
underpainting The first applications of paint that begin to block in color and loosely define the compositional elements. Also called ébauche.
vanishing point In perspective drawings, the vanishing point is the element in which the perspective lines converge in the distance. There can be one, two, or three vanishing points depending on the method used by the artist.
Versaillais Name given by the Communards to the French troops who, under the command of General Patrice de MacMahon, suppressed the Paris Commune of 1871. See “Paris Commune.”
vine or willow charcoal Long, thin charcoal sticks created by burning grape vines or willow twigs in a low carbon environment. Vine and willow charcoal produce brown to black shades. With magnification, the pastel particles often have a splintered appearance and display a characteristic sparkle.
Voltaire chair An armchair with a low seat and high back.
wash An application of thin paint that has been diluted with solvent.
watermark An identifying mark in a paper sheet which is created by tying wires to the papermaking mold. Watermarks are most easily viewed with transmitted light; however, some can be read with raking light.
weave interference A distortion that can occur when excess heat or pressure is applied to a painting, usually during the lining process. As a result, the original canvas weave texture becomes more pronounced or the weave texture of the lining material becomes visible on the painting surface. Also called weave emphasis or weave accentuation.
weir A dam constructed on a canal or navigable river to retain the water and regulate its flow.
wet-into-wet An oil painting technique which involves blending of colors on the picture surface.
wet-over-dry An oil painting technique that involves layering paint over an already dried layer, resulting in no intermixing of paint or disruption to the lower paint strokes.
wet-over-wet An oil painting technique which involves drawing a stroke of one color across the wet paint of another color.
wove paper One of the two types of paper. Wove papers may be either machine or handmade, and are produced from molds that have a woven wire mesh. The weave of the mesh can be so tight that it produces no visible pattern within the paper sheet, and often wove papers have a smoother surface than laid papers. Wove papers were developed during the mid-eighteenth century, but did not come into widespread use until later. The other type of paper is laid paper.
X-ray fluorescence spectrometry elemental mapping (MA-XRF) or XRF elemental mapping A non-destructive technique that entails collecting thousands of X-ray fluorescence spectra at regular intervals across a painting to build an alternate set of images depicting the locations and amounts of different elements. Although the information is fundamentally the same as measurements gathered from a single-point XRF, the graphical nature of the result is often a more powerful technique for understanding trends in an artist’s use of materials. The high number of spectra allows statistical manipulations of the elemental information to locate correlations between different pigments that would not be possible from a small number of tests. For example, the consistent occurrence of mercury along with chromium, and iron along with copper, could show that vermilion was used to mute the chrome green and red ocher was similarly employed in a mixture that includes emerald green. The resulting correlation maps then serve to show where the two cases occur in the composition. MA-XRF can also reveal preliminary paint applications that became covered as the composition was completed, thereby disclosing aspects of the painter’s method.
X-ray radiography (also referred to as x-radiography or radiography) Radiography is an examination tool analogous to the use of X-rays in medicine whereby denser components of a painted composition can be recorded as an inverted shadow image cast on film or a digital X-ray imaging plate from a source such as an X-ray tube. The method has been used for more than a century and is most effective with dense pigments incorporating metallic elements such as lead or zinc. It can reveal artist changes, underlying compositions, and information concerning the artwork’s construction and condition. The resulting image is called an x-radiograph or radiograph. It differs from the uses of X-ray spectrometry in being dependent on the density of the paint to absorb X-rays before they reach the film or image plate and being non-specific as to which elements are responsible for the resulting shadow image.
doi: 10.37764/78973.2.1010