Art Glossary

Acetate: A transparent, somewhat brittle plastic available in varying thickness and surface textures.

Acetone: A volatile, flammable liquid, C3H6O, used in paints and varnishes as a solvent. Dissolves acrylic paint. Can be used to clean dried acrylic paint from brushes and tools.

ACMI: Art and Craft Materials Institute. Independently certifies materials for toxicity, performance and quality.

Acrylic gesso: Acrylic polymer emulsion based with titanium dioxide and calcium carbonate, Contains sizing and ground. Suitable for flexible supports.

Acrylic latex paint: a.k.a. “House Paint”. An inferior polymer based paint. Not suitable as an artist grade paint.

Acrylic paint: Water soluble paint that dries to an insoluble paint film. Composed of two parts, an acrylic polymer emulsion (binder) and pigment.

Acrylic polymer emulsion: Made from acrylic resins. It is the binder that gives acrylic paint its handling and durability characteristics.

Acrylic resin: A polymer from which acrylic emulsions are made. High quality acrylic resin is a necessary component of high quality acrylic paint.

Acrylic watercolor: A technique where acrylic paint is diluted to the consistency of watercolor paint and applied to an absorbent surface. Color values are usually built from light to dark.

Additives: Any substance added to paint to impart valuable, physical or structural properties to the paint.

Alcohol: Solvent used to degrease oily surface prior to acrylic paint application.

Alkyd Paint: An oil or solvent compatible paint.

Aluminum Stearate: Wax-like material sometimes used for stabilizing oil paint.

AP Nontoxic: Certified nontoxic by an independent toxicological medical expert. No specific quality standards have been established. Nontoxic even if ingested.

Bevel-cut: Cutting or shaping the edge or end of a material to form an angle that is not a right angle, such as the bevel cut on the window edge of a mat.

Binder: The substance which holds the pigment in a paint, ground or drawing material.

Bright brushes: Used for short controlled strokes and impasto techniques.

Bristle hair brushes: Made of hog bristles. Stiff hairs, suitable for oil paint and/or acrylic paint.

Burnish: to make smooth or glossy by rubbing.

Cadmium: Pigments that are synthetic/inorganic. Although naturally occurring, they are process in laboratory and are classified as synthetic. Toxic in spray form.

Canvas: A woven fabric often used as a substrate for painting. Canvas is made from cotton, linen, jute and natural or synthetic fibers. Canvas is sold by width and by weight. The weight describes the thickness of a canvas and refers to the weight of a square yard of the material. (One square yard of 10-ounce duck, for example, weighs 10 ounces.) Canvases are available pre-stretched on either standard or heavy-duty stretcher bars.

Casein Paint: A heavy body water-based paint. The most inflexible and brittle of artist grade paints.

Chassis: Wooden frame, fixed or expandable, used to brace a wood-based board on which to stretch either paper or a canvas. Interchangeable with ‘stretcher’ and sometimes ‘frame’.

Chroma: Intensity or brightness of hue. The purity of color or its freedom from white or gray.

Cold press watercolor paper: Heavy weight watercolor paper. Cold press watercolor papers hold more water and warp less. Coldpress watercolor paper is rough and absorbent.

Collage: Collage is a technique where materials of different sizes and weights are glued to a backing surface. The collage materials and backing surface determine the type of glue to be used. Acrylic mediums are excellent glues for collage techniques. They provide easy, permanent, non-toxic adhering of most materials to any surface suitable for acrylic paint.

Cone: Slender pyramids made of ceramic materials used to determine the combined effect of temperature and time, which is sometimes called “heat-work”. Clays and glazes are fired to different points referred to by their cone equivalent or number.

Cotton duck: The most common canvas used and the most popular style.

Covering power: The extent of the area over which a given amount of liquid paint or varnish will spread to give a satisfactory coating when applied in a normal layer.

CP Nontoxic: Certified nontoxic by an independent toxicological medical expert. Meets or exceeds specific quality standards of material, workmanship, working qualities and color. Nontoxic even if ingested.

Cradled Board: Originally a hardwood panel with fixed strips along the grain and movable strips across the grain on the reverse, used to brace the board but still allow it to expand. Today, ‘cradles’ is used to mean a wood-based board which has been glued and screwed to a fixed chassis.

Damar Varnish: A petroleum distillate varnish used over a dried oil painting to affect its sheen.

Decoupage: The art of decorating something with cutouts of paper, linoleum, plastic, or other flat material over which varnish or lacquer is applied.

This process allows artists to transfer images generated from magazines, newspapers, photographs and laser printers onto any surface that will accept acrylic paint. It can be done with a wide variety of mediums depending upon your desired effect.

This technique transfers black & white and colored images. The medium is brushed, poured or troweled over the image to be transferred. After the medium has dried, it is soaked in water and the paper is removed from the back of the image. You are left with a transparent to translucent image that is imbedded within acrylic medium.

Distilled Turpentine: Used to thin oil paints. It is an acute toxic hazard.

Double Stretched Canvas: Two layers of canvas stretched on one frame.

Drag: The surface tension of a paint (usually applied with a brush) along a surface.

Dry Brush Technique: Using a dry brush almost free of paint to stroke in highlights and shading, producing a scratchy effect.

Drying Oil: Vegetable oil which dries to a film by oxidation.

Eggshell canvas surface: Paper smooth canvas surface that is excellent for portrait and airbrush techniques.

Emulsion: A pigment mixture normally based on water and acrylic that is used as paint.

Essential Oil: Extracted from plants, an oily liquid which is partly volatile.

Extenders: An additive that increases the volume of paint, without changing color or opacity.

False wall: In mural painting, it is a wall erected in front of an existing wall. It eliminates the dangers inherent in expansion and contraction of plaster and masonry. It also protects against cracking, peeling and water damage and allows for easy removal of the mural. The mural wall can also be a stretched canvas panel or canvas adhered to a rigid panel. A false wall for interior murals allows the artist to paint the mural in the studio rather than on location.

Fan brush: Used for blending surface color.

Ferrule: The metal wrapping on a brush that attaches the bristles to the handle. A Ferrule should be double crimped, seamless with epoxy glue.

Filbert brush: Used for thick to thin strokes without hard edges. Shaped like a flat or bright with rounded corners.

Fillers: Mistakenly thought to be all additives to paint which increase volume without adding any intrinsic qualities to the paint. In truth, it is any substance which when mixed with pigment causes no appreciable change in shade or hue. Used largely as adulterants or cheapeners, many are used to impart valuable, physical or structural properties to paint. See additives.

Fixative: Fixative simply 'fixes' soft drawing materials like charcoal, chalks and pastels so that they do not smudge and the finished drawing remains intact as the artist intended; preserving the applied medium on the paper. Fixative can be considered somewhat similar to lacquer or varnish however only a very thin coat is required and it has a matte finish.

Flat brush: Square end for softer and more subtle brush strokes.

Flexibility: The ability of a material to bend or twist. While acrylic colors and mediums will remain flexible over time, all acrylic paint films become increasingly brittle in cold weather. Do not flex, roll or unroll acrylic paintings in temperatures below 45 degrees.

Floorcloth painting: May be thought of as paintings on canvas that lie on the floor instead of hanging on the wall. Being placed on the floor subjects the painting surface to abrasion and dirt that a wall hanging does not encounter. Because of this, floorcloth paintings are prepared differently.

Fluorescent paint: Reflects more visible light than it receives. Fugitive colors.

Fresco: A painting technique of applying paint to wet plaster. Used during the Italian Renaissance, i.e. The Last Supper, by Da Vinci.

Frisket: Frisket films are sheets of thin (usually 3-mil) clear vinyl with a low tack adhesive on one side. A material that protects covered areas from overspray.

Fugitive Color: A color made of pigment that is susceptible to fading when exposed to ultraviolet rays (sunlight).

Gesso: A primer used as a surface preparation for painting.

Glaze: A mixture of mostly gloss medium & varnish and a little paint. Used in acrylic painting techniques to create luminous color and depth.

Glazing: Transparent color over dry underlayer, used to create spatial and/or optical color effects. Oil color offers the widest manipulative possibilities in glazing but any transparent medium can offer glazing too.

Gloss: Highest reflective surface. The most “shiny”.

Gouache: Often also called 'designers paint' and 'poster paint' it is soluble in water, and has a chalky base, it dries with a flat color. Gouache is similar in characteristics to watercolor paint except that it is more opaque.

Ground: Layer on support which can alter in color, absorbency or texture. ‘Primer’ is also used for ‘ground’.

Grout: A paste cement or mortar used for filling and sealing gaps, cracks, crevices and joints – especially between tiles.

Gum: Hardened sap of plants which is either water-soluble or absorbs water.

Handle: On a brush, should be made of seasoned hardwood dowel, tapered at both ends.

Handling Properties: Group of properties which reflect smoothness, brushability, spreadability, tactility, etc.

Hot Press: A type of watercolor paper. It has a smooth finish, due to being pressed with “hot” rollers during manufacturing.

Hue (Label): When “Hue” is added to the name of a paint (i.e. Cadmium Red Hue) it is a color that is a mixture of pigments that simulate pure cadmium colors. “Hue” colors are less expensive and can be more lightfast than traditional pigments.

Humidifier: Substance or thing which retains moisture or prevents it escaping.

Impasto: A technique of painting with brush or palette knife using thick applications of paint, which stand out in relief.

Impressionist: The term impressionism most commonly refers to a group of French painters who did the majority of their work from 1865 until 1910. The group of painters included Edouard Manet, Claude Monet, Camille Pissarro, Edgar Degas, Alfred, Sisley, and Auguste Renoir. Instead of painting a picture from an emotional point of view, impressionist artists tried to capture immediate impressions of objects and scenes. Impressionist painters concentrated on elements of color, light, and texture. Artists of this time period also used broad brushstrokes and applied paint in small spots of pure color instead of mixing colors. They rarely used grey or black paint. For this reason, many impressionist paintings seem to have a shimmering brilliance.

Imprimatura: Colored veil over a white ground.

Inorganic pigments: Pigments without carbon, such as cadmiums, cobalts, earth colors. Derived mostly from metals. Tend to be opaque, low value, low chroma, high opacity and chemically stable.

Intensity: The brightness or strength of a color.

Interference paint: “Pearlescent Color”. Polymer emulsion with titanium coated mica flakes. Painted over a dark color you see the labeled interference color. Painted over a light color you see the complementary color. Color changes depending upon viewing angle.

Iridescent paint: Also known as “metallic” paints that do not tarnish. They mimic the effect of bronzing powders. Bronzing powders can not be used with acrylic emulsions as they tarnish due to the alkalinity of the binder.

Jute canvas: Used in applications that call for extreme texture, as well as lower price. Not considered a permanent surface and is too textural for most work. Just as with paper, surface texture is an important factor to consider when choosing a canvas.

Key: Rough surface.

Kolinsky Sable: Highest quality brush. Made of the male Tartar Martin (weasel). For watercolor, washes and fine detail.

Kopal (Copal): An additive for oil paint, used to promote drying.

Leach: Rolling polymer clay into thin sheets and sandwiching them between sheets of paper. Over a period of hours, the plasticizer will leach or wick into the paper and a firmer clay results.

Lightfast: Resisting fading on long exposure to sunlight. When applied to paint it means absolute permanence.

Lightfastness I: Excellent lightfastness. No change for 100 years of museum light. Best for outdoor work.

Lightfastness II: Very good lightfastness. Satisfactory for indoor applications.

Lightfastness III: Fugitive lightfastness. Not recommended for permanent applications.

Linen canvas: Superior strength and longevity. Lacks the consistency or texture of cotton. Portrait quality linen has the finest and most consistent weave. Although linen is preferred as a “professional” surface, when used for acrylics, it offers little benefit over cotton. The high oil content of linen may make it less suitable for use with acrylic gesso and paint.

Liner: Produces continuous lines without reloading. Great control for rendering and lettering.

Liquin: A solvent used in oil painting, made from oil modified alkyd resin.

Livering: Solidification of oil paint within its tube, caused by poor quality pigments or grinding. Nowadays, it is not likely to occur in paint made for artists.

Mahlstick: A long rod with a padded end, used to steady your hand against a painting.

Marbling: Marbling is a single print process, done by manipulating paint that is floated on the surface of a thickened water solution. The floating paint is then transferred from the water onto paper, fabric or any other porous surface.

Masking: Protecting dry paint film from new paint application through the use of masking tapes and fluids.

Masking fluid: Rubber latex solution used to mask out areas on paper.

Matte: The least reflective surface. The most “dull”.

Media: Plural of medium in sense of particular method, e.g. oils, watercolor, etc.

Medium: An additive mixed into the paint to change the working characteristics of the paint, without decreasing its adhesion. Acrylic mediums change the paint so it can be sued for a variety of techniques.

Mineral oil: Type of oil refined from petrol.

Mineral spirits: A petroleum distillate used to thin oil paints. It is an acute toxic hazard.

Mineral wax: Wax/es refined usually from petrol.

Mixed pigment colors: Gives artists the benefit of pre-mixed, “custom” colors. Colors are brighter than can be mixed in studio, cuts down on color mixing and provides cost savings. Mixed pigment hue colors give artists the choice of using a hue color as a replacement for the true or target color.

Mop brush: Full bodied to hold lots of liquid. Used for washes.

Mordant: Prepares the surface of paper or fabric for quick adhesion of paint. Used in marbling.

Mosaic: A picture or decorative design made by setting small colored pieces , as of stone or tile, into a surface.

Mull, Mulling: Grind, grinding (rubbing) pigment with muller and plate (slab).

Mural painting: Murals include a variety of techniques including fresco, encaustic, mosaic, stained glass and photography. The type of mural of most interest to contemporary artists is either painting on canvas, which is then attached to a wall, or painting directly on the wall surface itself.

Mylar: A film that has all the properties and uses of acetate with additional flexibility and strength. Much higher in price than acetate, it does not stretch, crack or yellow and is also available with a photosensitive surface for the reproduction of line drawings.

Natural pigments: Pigments occurring in nature. More consistent and least costly to produce. Can be organic or inorganic.

Natural/Inorganic pigments: Generally pigments of low value, low chroma and high opacity. Chemically stable.

Natural/Organic pigments: Pigments of vegetable or animal origin. Generally not as lightfast, as high in chroma or as chemically stable in acrylic paint as synthetic pigments.

Oil paint: Made of linseed oil (binder) and pigment. Soluble in oil based solvents (turpentine, mineral spirits).

Opacifiers: Increase the opacity of paint. Inhibit the ability of light to pass through the paint.

Opacity: The degree to which a pigment obscures a substrate or the degree to which light passes through the paint. Also known as “hiding power”.

Opaque: Opaque paint does not allow the light to transmit through the paint. This is important for covering imperfections and for retention of true color in many instances.

Open time: Drying time of paint. Open time varies according to temperature, humidity, absorbency of surface and air flow above surface while working. Lightly misting surface with water during application will increase open time.

Organic pigment: Pigments that have carbon as a derivative. Originally extracted from plant or animal matter. Tend to be transparent.

Ox hair brush: Strong body, especially suited for oil paint or heavier colors.

Palette: Assortment of limited group of colors chosen for use in painting.

Palette knife: Intended for mixing paint, they are generally long, straight, and have a rounded snub nose. They are relatively stiff and don’t usually have a crank in the shaft.

Parchment: Prepared skin of sheep or goat, mainly for calligraphy.

Permanency: The ability of a color to withstand any color shifting or fading when exposed to ultraviolet light.

pH of paper: Measure of acidity. pH7 indicates a paper which is acid-free.

Photo emulsion: A paste type substance, that when coated onto a mesh with a scoop coater, it dries to form a photographic type of film.

Pigment: The powdered coloring agent that is mixed with a binder such as oil, acrylic or gum to make various artists paints, pastels, chalks, and other materials for making artwork.

Polymer emulsion: The binder for acrylic paints.

Polymerized oil: See Stand Oil.

Primer: An application that seals and protects a surface for the application of paint. It is used in acrylic and oil painting.

Priming: The preparation of a surface upon which to paint using sizing and ground.

Resin, Natural: Hardened sap of plants which is insoluble in water.

Resin, Synthetic: Resinous compound, usually synthesized from petrol.

Rheology: How sticky or slippery paint feels as it’s being applied to a substrate. The term “brush drag” refers to the rheology of the paint.

Round brush: Versatile. Good for thick to thin strokes and detail.

Sable brush: Good quality. Made from female Tartar Martin (weasel).

Sabeliene brush: Specialty treated silken lighter colored ox hair that resembles sable in working quality.

Saturation: The degree of a color intensity or vividness.

Script brush: Elongated shape. Optimal control for lettering or line work.

Semi-gloss: In-between gloss and matte.

Shading: Changing the value of a color, usually by adding black.

Sheen: The reflective quality of a dried paint surface.

Shellac: Resin secreted by stick insects on certain trees, mainly in India. Available in a number of grades.

Single pigment color: Offers artists the purest color, to be used alone or in color mixing. Includes cadmiums, cobalts, quinacridones (ACRA), phthalocyanine (phthalo) and other colors.

Sinking paint: Layer of paint which sinks into underlayer.

Sizing: Protects substrate (canvas) and provides receptive surface for ground.

Solvent: A material used to thin (dilute) paint.

Stand oil: Stand oil can be assumed to be linseed stand oil. Stand oil is a drying oil which has been processed by heat. It can also be called polymerized oil.

Stippling: A dry brush painting technique, using a stiff brush.

Stretcher: See Chassis.

Substrate: Surface upon which any paint is applied. (canvas, paper, wood, etc.)

Substrate induced discoloration (SID): When acrylic mediums are used as a size for primed or unprimed cotton, linen, wood or hardboard, the water content may draw impurities out of the support as it dries. A yellow or brown discoloration in the medium may occur over time. It will only be noticeable in areas that are left unpainted. It occurs with all acrylic mediums currently used by major fine art paint manufacturers. Washing the canvas before use can greatly decrease or eliminate SID. It is not a problem if the mediums are mixed with paint or painted over.

Support: Material which supports the ground and painting or drawing.

Surface: The surface, also known as the support or substrate, is the basic substructure of a painting. The type of surface chosen will depend somewhat on the painting style of the artist, the desired visual effect, the purpose of the work, required longevity and the media used.

Surfaced: Rough surface.

Synthetic canvas: Most uniform in texture, exceptionally strong and long-lasting. As temperature increases above 90°F some synthetics do not maintain proper surface tension. This is temporary and the canvas usually returns to normal with lower temperatures.

Synthetic pigments: Source of most pigments today. Formulated to mimic the effects of natural pigments. Can be organic or inorganic.

Synthetic/Inorganic pigments: Pigments of low value, low chroma, high opacity, high lightfastness.

Synthetic/Organic pigments: Pigments containing carbon. High chroma, transparent or translucent pigments.

Tempera paint: Water based paint that is redissolveable when dry. Best on rigid supports.

Tesserae: One of the small squares of stone or glass used in making mosaic patterns.

Thickeners: Additives that change the viscosity (thickness) of paint.

Thinning: To reduce concentration by adding an associated solvent. Thinning increases penetration and can make it easier to apply mediums and varnish. Over thinning may result in weak varnish film, poor adhesion, running and soaking into substrate.

Tinting: Adding white to a color.

Tinting strength: Tinting strength of a pigment refers to how strong a color it is. Measured by how much pigment it takes to change color to white.

Tole painting: A decorative art technique. Originally from Eastern Europe.

Tooth: Rough surface.

Toothed: The surface of a sheet of paper, or the surface of a dried paint film or ground. (i.e. tooth of gesso), which assists in the application and bonding of subsequent coats of paint.

Toxicity: The degree with which a product will be hazardous to people or the environment.

Translucent: In-between transparent and opaque. Suitable for glazing and other techniques.

Transparent: The least opaque paint. Least amount of “hiding power”. Best suited for glazing techniques.

True gesso: A sizing made of animal glue and calcium carbonate (inflexible supports).

Underpainting: The first layer (or first few layers) of a painting upon which the final imagery is painted. Often the underpainting is totally covered by the top layers.

Value: Relative lightness of a color (light vs. dark).

Varnish: A clear coating applied over artworks to protect against dirt, smoke, ultraviolet radiation, abrasion, and other environmental hazards that art is subject to. It is also commonly used to change the surface sheen and appearance of colors, so can be regarded as a creative tool. Apply over dry paint.

Vehicle: The liquid used as the carrier of pigments in paint. The binder in a paint. In acrylic paint the vehicle is polymer emulsion.

Veil: See imprimatura.

Vellum: A type of translucent paper that resists sticking to tacky surfaces.

Viscosity: The thickness of a paint. Its ability to flow.

Wash: A mixture of (mostly) water and (a little) paint. Used in watercolor techniques.

Watercolor paint: A water based paint that is redissolveable when dry. The binder is Gum Arabic.

Wetting agent: Usually a detergent-based liquid which breaks surface tension of a binder, and ‘wets’ the pigment or support.