Glossary

In this post, I have shared a few definitions that readers may find useful. Many of these definitions have been adapted from Simon Jennings’ Artist’s Color Manual.

albumen

egg white; different from “albumin,” the specific protein found in the egg white

albumin

a family of water-soluble proteins that can be found in egg white, milk, and blood

ASTM

acronym for the American Society for Testing and Materials, now ASTM International, a standards organization that develops and publishes technical standards for products and materials, including artist materials

binder

a liquid that is mixed with pigment for form paint; in tempera painting, the binder is a mixture of egg yolk, distilled water, and vinegar

chroma

a term to describe the purity of a color (a color that contains little to no gray); see Munsell Scale

contrast

the degree of difference between the light and dark tones in a painting

earth colors

colors that are made from naturally occurring pigments like oxides, ochres, umbers, and siennas

egg tempera

paint made from a binder of egg yolk, distilled water, and vinegar combined with powdered pigment; this paint dries very quickly to leave behind a hard surface with a satin finish; see also temper

found colors

colors that can be obtained from nontraditional sources, such as natural materials, liquids, and food

gesso

mixture of chalk and glue size (natural or synthetic) traditionally used as a ground for tempera painting

gilding

application of gold leaf to give the appearance that an object is made of solid gold

glaze

transparent or semi-transparent layer of color painted over another color to modify or enhance its effect

ground

a priming layer that protects the support and provides a surface for painting; in egg tempera, a common ground is traditional gesso

gum arabic

a water-soluble gum made from acacia trees; the typical binder for watercolors that can also be added to increase gloss and transparency

hatching

a method of applying color or shading using close, parallel strokes

icon

a stylized image of a holy figure, such as Christ or the Virgin Mary, usually painting in the Byzantine style

imprimatura

a layer of diluted color applied to a ground to tone down its brightness prior to applying subsequent layers of paint

lightfastness

property of pigment that describes how resistant it is to fading when exposed to light

luminosity

the quality of reflecting light where areas of white paper show through

medium

the type of material used in a drawing or painting (eg. egg tempera), plural “media;” also refers to substances that can be combined with paint to change its character, plural “mediums”

mis en place

a French culinary phrase meaning “everything in its place"; refers to the setup of tools and ingredients before cooking

Munsell scale

a three-dimensional scale used in specifying color, developed by Albert Munsell

opacity

the degree to which a color or medium can cover the surface underneath

optical mixing

technique of painting small areas of color, like dots or hatches, next to each other so that they appear to mix when viewed from a distance

palette

the surface on which paints or colors are mixed; also refers to the selection of colors used by an artist

permanence

the degree to which a pigment is lightfast, see lightfastness

pigment

the coloring agent in paint, usually refered to in powdered form

PVA

abbreviation for polyvinyl acetate, best known as white glue, wood glue, or Elmer's glue; a rubbery synthetic polymer that is used in many modern art materials

rabbit skin glue

a glue or sizing made from refined rabbit collagen, usually sold as powder or granules

RSG

common abbreviation for rabbit skin glue

refractive index

the measure of the bending of a ray of light when passing from one medium to another

size

a thin glue applied to a support prior to gesso; traditionally, rabbit skin glue or hide glue was used, but now cruelty free options like acrylic or PVA size are available

solvent

agent that thins or dissolves paint or pigment; in egg tempera, water is used as a solvent

support

the surface on which a drawing or painting is made; in egg tempera, the support is usually a wood panel or board

temper

a mixture of powdered pigment and water, usually mulled with a glass muller or mortar and pestle; pigment is tempered to make it easier to mix with a binder

tempera

painting on an absorbent gesso ground with emulsion paints which can be thinned with water, according to Ralph Mayer in The Painter's Craft

transparency

the degree to which light can pass through a color; see also opacity

vanishing point

in perspective, the point in which parallel lines converge as they meet the horizon