Part of The Grand Glossary: A Collector's Reference. This section covers the specialist vocabulary of original prints, drawings, watercolours, and works on paper, from the mechanics of printmaking processes to the assessment of condition, the interpretation of inscriptions, and the legal frameworks governing provenance. Terms are arranged alphabetically within thematic groupings.
Printmaking Processes: Intaglio
Aquatint
An intaglio printmaking technique that produces areas of tone rather than line, by treating the surface of a copper or zinc plate with a layer of acid-resistant resin dust before biting with acid. The acid bites around each resin particle, creating a pitted surface that holds ink and prints as a fine, granular tone. The depth of tone is controlled by the duration of the acid bite: a brief bite produces pale grey; a long bite produces deep black. Aquatint is almost always combined with etching to provide linear definition. It was developed in the mid-18th century and was the dominant medium for tonal print reproduction in the late 18th and early 19th centuries. Francisco Goya used aquatint to extraordinary expressive effect in the Caprichos and Disasters of War series.
Drypoint
An intaglio technique in which a design is scratched directly into a metal plate using a hard, pointed instrument — a steel needle, a diamond, or a tungsten carbide point — without the use of acid. The drypoint tool displaces metal to either side of the scratch, creating a rough, feathery ridge of displaced metal called the burr. The burr holds ink and prints as a characteristically soft, velvety, slightly blurred line quite unlike the clean, precise line of an engraving. Drypoint burr is fragile and wears rapidly under the pressure of printing; early impressions from a drypoint plate are therefore significantly richer and more valuable than later ones. Rembrandt van Rijn used drypoint to supreme effect in his late etchings, often combining it with etching and engraving on the same plate.
Engraving
An intaglio technique in which a design is cut directly into a metal plate — copper until the 19th century, then increasingly steel — using a burin, a hardened steel tool with a lozenge-shaped or square cross-section. The burin removes a clean curl of metal and leaves a precise, V-shaped groove that holds ink. Engraved lines have a characteristic swelling and tapering quality as the burin is pressed and released; cross-hatching creates areas of tone. Engraving was the dominant reproductive printmaking technique in Europe from the 15th to the late 18th century and was used for the reproduction of paintings, book illustration, maps, and portraiture. It requires great technical skill and is one of the most demanding of all printmaking processes.
Etching
An intaglio technique in which a metal plate (copper, zinc, or steel) is covered with an acid-resistant ground, through which the artist draws with a needle to expose the metal, and then immersed in acid (the mordant). The acid bites into the exposed metal, creating the printing lines. The depth of the bite, and therefore the darkness of the printed line, is controlled by the duration of immersion. Areas not to be bitten are stopped out with varnish at intervals. Etching produces a freer, more spontaneous line than engraving, as the artist draws through the ground rather than cutting metal directly. Rembrandt, Goya, and Whistler are among the supreme masters of etching.
Mezzotint
An intaglio technique that works from dark to light, in which the entire surface of a copper plate is first roughened with a toothed tool called a rocker, creating a uniformly pitted surface that would print as a dense, velvety black. The design is then created by burnishing the roughened surface selectively to varying degrees of smoothness: fully burnished areas hold no ink and print as white; partially burnished areas print as intermediate tones. Mezzotint produces an unparalleled range of continuous tone and velvety shadow and was the dominant technique for the reproduction of oil paintings in 18th-century England, where it was known as the black art. The mezzotint plate wears relatively rapidly; early impressions, before the plate has been significantly reworked, are the most valued.
Stipple Engraving
An intaglio technique in which tone and form are built up from a pattern of small dots and flicks rather than lines, producing a soft, granular effect well suited to the reproduction of paintings and the depiction of flesh. Stipple engraving was developed in the mid-18th century and was widely used in England for reproductive prints after fashionable portraits and subject pictures. Francesco Bartolozzi, who came to England in 1764, was its greatest practitioner and produced many of the finest stipple engravings after Reynolds, Kauffmann, and Cipriani.
Printmaking Processes: Relief
Linocut
A relief printmaking technique in which a design is cut into a flat sheet of linoleum using gouges and knives, with the raised (uncut) areas inked and printed. Linocut is technically simpler than woodcut and allows freer, more fluid cutting, but lacks the grain texture of wood. It was adopted widely by artists in the early 20th century; Picasso used it to develop his multi-colour reduction linocut technique in the 1950s and 1960s. Linocuts are identified by the smoothness of their printed surfaces and the absence of wood grain in the background.
Woodcut
The oldest and simplest of all printmaking techniques, in which a design is cut in relief into the plank side of a wooden block, with the raised areas inked and pressed onto paper. The grain of the wood runs with the block and may print as a visible texture in background areas. Woodcut was the primary medium for European printed book illustration and broadsheet production from the late 14th to the early 16th centuries; Albrecht Dürer elevated it to a major artistic medium. The technique was revived in the late 19th century by Paul Gauguin, Edvard Munch, and the German Expressionists, who exploited the roughness and grain of the wood for expressive effect.
Wood Engraving
A relief technique in which the design is cut into the end grain (rather than the plank side) of a very hard wood, typically boxwood, using engraving tools. End grain allows for much finer detail than woodcut. Wood engraving was the dominant technique for black-and-white magazine and book illustration throughout the 19th century, as it could be set alongside moveable type in the press. Thomas Bewick, who refined the technique in the late 18th century, produced wood engravings of extraordinary delicacy. The technique was revived by studio printmakers in the 20th century.
Printmaking Processes: Planographic
Lithography
A planographic printing process based on the mutual repulsion of grease and water, in which the design is drawn or painted onto a flat surface — traditionally a block of Bavarian limestone, later a zinc or aluminium plate — with a greasy medium (crayon, tusche, or ink). The stone or plate is dampened with water, which is repelled by the greasy design areas; when oil-based ink is applied, it adheres only to the design. Lithography allows the artist to draw on the printing surface with complete freedom and reproduces the drawn mark with great fidelity, including the grain of the crayon and the flow of the brush. Invented by Alois Senefelder in 1798, it became the dominant reproductive printmaking process of the 19th century and a major original art medium.
Screen Printing (Serigraphy)
A planographic printing process in which ink is forced through a fine mesh screen — originally silk, now synthetic — onto the surface beneath, with areas not to be printed blocked out by a stencil or photo-emulsion resist. Screen printing produces flat, opaque areas of colour with great intensity and was adopted by Pop artists including Andy Warhol, Roy Lichtenstein, and Eduardo Paolozzi as a medium precisely suited to their imagery. Original screen prints are distinguished from commercial printing by the texture of the mesh impression and the opacity of the ink layers.
Editions, States, and Impressions
Artist's Proof (A/P or E/A)
Impressions printed outside the numbered edition, originally reserved for the artist’s personal use. Artist’s proofs are typically marked A/P (artist’s proof) or E/A (epreuve d’artiste) and are usually limited to approximately 10% of the edition size. They are technically equivalent in quality to numbered impressions but may carry a premium in the market due to their association with the artist’s personal archive. The term has been used loosely and sometimes misleadingly in the modern print market; buyers should be alert to editions in which the number of A/Ps is disproportionately large.
Cancellation Proof
An impression taken from a plate, block, or stone after the edition is complete, with the printing surface defaced — typically by scoring, drilling, or stamping — to prevent further printing. Cancellation proofs serve as documentary evidence that the edition has been properly closed. They are sometimes sold as curiosities or documentation; the cancellation mark is an integral part of their interest and significance.
Edition
The total number of impressions printed from a given plate, block, stone, or screen in a single print run, typically fixed in advance and recorded. Modern limited editions are numbered in pencil by the artist in the format impression number/total edition size (e.g. 14/75, meaning the fourteenth impression of an edition of seventy-five). The concept of the limited signed edition was established in the late 19th century by etching revivalists including Francis Seymour Haden and James McNeill Whistler. Before this period, prints were produced in open editions determined by market demand and the wear of the plate.
Impression
A single printed sheet pulled from a plate, block, stone, or screen. The quality of an impression — the evenness of the inking, the pressure of printing, the paper used, the freshness of the plate — is a primary determinant of value in prints of all periods. The best impressions from a plate are typically the earliest, before the plate has worn; in the case of drypoint, early impressions may be dramatically superior to later ones due to the rapid deterioration of the burr.
State
A distinct version of a print produced at a different stage of the plate’s development, representing a record of the artist’s working process. A plate may pass through many states as the artist adds detail, corrects passages, or alters the composition; each state produces impressions that differ from the others. States are documented in catalogue raisonnés and may vary significantly in rarity and desirability. First states — early working proofs before the plate is complete — may be extremely rare and highly valued; later states may represent the plate’s full development. Rembrandt’s etchings are among the most thoroughly documented works in terms of states, with some plates passing through five or more recorded states.
Drawings and Works on Paper
Bistre
A brown ink or wash made from the soot of wood smoke, dissolved in water. Bistre was widely used by Old Master draughtsmen from the 15th to the 18th centuries, often in combination with pen and ink. It has a warm, golden-brown tone that may fade or shift in colour over time. Rembrandt used bistre wash extensively in his drawings. It is distinct from sepia, which is made from the ink sac of the cuttlefish and is a colder, darker brown.
Chalk
A drawing medium used in its natural forms — red chalk (sanguine), black chalk, and white chalk — or in fabricated stick form. Red chalk (iron oxide in a clay matrix) was one of the most widely used drawing media of the Italian Renaissance and the 17th and 18th centuries, valued for its warmth and its ability to suggest flesh tones. Black chalk (a carbonaceous shale) produces a denser, cooler line. The trois crayons technique, developed in France in the 18th century, combines all three chalks on tinted paper to produce drawings of great richness and tonal range.
Gouache
An opaque water-based paint made by adding white pigment (or chalk) to watercolour, producing a matt, chalky surface. Gouache handles differently from transparent watercolour: it can be applied over darker passages, allows for sharp-edged, flat areas of colour, and dries to a slightly lighter tone than when wet. It was widely used for miniatures, decorative designs, and illustrations and is associated with the great tradition of Persian and Mughal manuscript painting. European artists including Paul Sandby and J.M.W. Turner used gouache in combination with transparent watercolour.
Pastel
A drawing and painting medium consisting of pure pigment bound with a minimal amount of gum or resin and compressed into sticks. Pastel produces an intensely coloured, powdery surface that is vulnerable to disturbance and requires fixing or careful framing behind glass. It was elevated to a major artistic medium in the 18th century by Maurice-Quentin de La Tour, Jean-Baptiste Perronneau, and Rosalba Carriera for portraiture, and by Edgar Degas in the 19th century. Pastels are assessed for the freshness and vibrancy of their colour, the condition of the surface, and the quality of the support.
Watercolour
A painting medium in which finely ground pigments are bound with gum arabic and applied in transparent washes with water. The luminosity of watercolour depends on light passing through the transparent paint layers and reflecting back from the white paper beneath. English watercolour of the late 18th and early 19th centuries — associated with artists including Paul Sandby, Thomas Girtin, J.M.W. Turner, John Constable, John Sell Cotman, and David Cox — represents one of the great traditions of European landscape art and is a significant collecting field in its own right. Condition is a critical issue in watercolour collecting, as the medium is highly susceptible to fading and light damage.
Paper and Support
Chain Lines and Laid Lines
The pattern of lines visible in laid paper when held to the light, caused by the wire mesh of the papermaking mould. Laid lines are the closely spaced parallel lines running across the sheet; chain lines are the more widely spaced lines running at right angles to them, corresponding to the wires that hold the laid wires together. The spacing of chain lines and the presence of watermarks are used in the dating and identification of papers. Wove paper, in which the mesh is uniformly woven rather than laid, produces a smooth, even surface without visible lines and was not developed until the mid-18th century.
Foxing
Small, irregular spots of brown or reddish-brown discolouration found on the surface of paper, typically caused by a combination of fungal growth and oxidation of metallic impurities in the paper. Foxing is extremely common in works on paper from the 18th and 19th centuries and ranges from scattered spots that do not significantly affect the image to dense, widespread staining. It can be partially treated by specialist paper conservators but cannot always be fully removed. In assessing a work, the location of foxing relative to the image is as important as its extent.
Laid Paper
Paper made on a mould of parallel wires (the laid lines) supported by more widely spaced wires at right angles (the chain lines). Laid paper was the standard paper type for printing and drawing from the introduction of paper to Europe until the mid-18th century and remains in use for fine art and printing purposes. The texture of the laid lines is visible in raking light on the surface of the paper and as a pattern of light and shadow when the sheet is held up to transmitted light.
Watermark
A design or lettering formed in the papermaking mould by a wire pattern that produces a thinner, more translucent area in the finished sheet, visible when the paper is held to the light. Watermarks were used by papermakers to identify their product from the 13th century onwards and are an important tool in dating and localising paper. The identification of watermarks is a specialist discipline; catalogues of watermarks — most notably those compiled by Briquet and by Heawood — allow many papers to be dated and attributed to specific mills.
Condition
Fading
The loss of colour intensity in a work on paper, caused by exposure to light (particularly ultraviolet radiation), atmospheric pollutants, or the inherent instability of certain pigments or dyes. Fading is irreversible; no conservation treatment can restore lost colour. The fugitive nature of certain historical pigments — indigo, Prussian blue, and many early synthetic dyes — means that some works have changed significantly in appearance from their original state. Works should be stored and displayed away from direct light and UV sources.
Mat Burn (Mount Burn)
A yellow-brown staining or line of discolouration on a work on paper, caused by acid migration from a mount or mat board of poor quality into the paper of the work. Mat burn is particularly associated with wood-pulp boards used in the 20th century, which contain lignin and other acidic materials. It typically manifests as a brown line corresponding to the inner edge of the mat opening. Mat burn can be partially treated but is difficult to reverse fully; the use of archival, acid-free mounting materials prevents its recurrence.
Plate Mark
The indentation left in a sheet of paper by the edge of an intaglio printing plate under the pressure of the printing press. The plate mark is visible as a slight embossed rectangle or oval around the printed image and is a characteristic feature of intaglio prints. Its presence confirms that a print was produced by intaglio means; its absence from a work claimed to be an intaglio print is a significant warning sign. The plate mark may be trimmed away on prints that have been mounted or reframed, which reduces value.
Trimmed Margins
A condition in which the margins of a print or work on paper have been cut down from their original dimensions, whether to fit a frame, remove damage, or improve appearance. Trimmed margins reduce value in proportion to their extent: a print with ample, even margins is more desirable than one trimmed close to the image. In the case of prints with decorative or informative letterpress below the image, trimmed margins may remove the title, artist’s name, or publication line. Margins are measured and reported in catalogue descriptions.
Provenance and Legal Frameworks
Catalogue Raisonné
A comprehensive, scholarly catalogue of all known works by a given artist, typically organised chronologically or by medium, with full descriptions, dimensions, condition notes, exhibition history, provenance, literature references, and illustrations. The catalogue raisonné is the fundamental reference tool for the study and market of an artist’s work. Inclusion in the catalogue raisonné is a significant indicator of authenticity; works not included may be authentic but undocumented, or may be rejected as not by the artist. Some artists have no catalogue raisonné; for others, multiple competing catalogues exist with differing attributions.
Collector’s Mark
A stamp, seal, or other mark applied by a collector to a work on paper to record their ownership. Collector’s marks are documented in Frits Lugt’s Les Marques de Collections, a fundamental reference work that lists thousands of recorded marks with their owners’ biographies. The presence of marks from notable historical collections — the Mariette, Crozat, Reynolds, or Lawrence collections, for example — adds significantly to the interest and value of a work and contributes to its provenance chain.
Export Licence
A licence required for the export from the United Kingdom of cultural property meeting specified criteria of age and value, under the Export Control Act 2002 and associated statutory instruments. Applications are considered by the Reviewing Committee on the Export of Works of Art and Objects of Cultural Interest; a deferral may be granted to allow a UK institution to acquire the work at the fair market price. Buyers of significant works should be alert to export licence requirements, which may affect their ability to remove a purchase from the country of sale.
Provenance
The documented history of ownership of a work from its creation to the present day. A full provenance chain records every owner, the dates and means of transfer between owners, and the relevant documentation. Provenance serves multiple purposes: it contributes to the authentication of a work; it establishes that the work is free of legal claims; and it adds historical and associative interest. Gaps in provenance, particularly for the period 1933–1945, require careful investigation under the Washington Principles on Nazi-Confiscated Art and the London Declaration. UK auction houses and dealers are required to conduct due diligence on provenance and to check works against databases of stolen and looted cultural property.
Washington Principles
Non-binding principles agreed at the Washington Conference on Holocaust-Era Assets in 1998, committing signatory nations to identify art confiscated by the Nazi regime between 1933 and 1945, to publicise such works, and to seek fair and just solutions with the heirs of the original owners. The principles apply to works in public collections and to works offered for sale through the commercial market. Dealers and auction houses are expected to conduct due diligence on works with gaps in provenance covering the period 1933–1945 and to check works against established registers of looted art, including the Art Loss Register.
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