Alkyd – Alkyd resin is heat polymerized oil. Polymerization is merely the linking up of individual molecules in chains.
Alkyd resins are made from a number of oils. The soy oil based alkyds are the ones primarily used in artists materials since they have all the excellent properties of alkyd but keep their color the best, much better than linseed oil
Alla Prima – Oil painting technique in which the entire painting is completed in one sitting.
Binder – The substance in a paint which holds together (binds) the pigment and makes the paint adhere to the support.
Chiaroscuro – An Italian word literally meaning “light dark”, used to describe the skillful balance of light and dark in a painting with strong contrasts to create dramatic effect.
Chroma– The relative intensity or purity of a hue when compared to grayness or lack of hue.
Etching – A printmaking technique in which a drawing is made through a wax covering on a metal plate, which is then put into acid to eat away (etch) the metal where it has been uncovered. The plate is then inked and printed.
Fat – A term used to describe the high oil content in paints and mediums.
Gallery Tone – The yellowish color of old paintings usually caused by the ageing of natural resins used in a painting or varnish.
Glazes – The term used for a thin, transparent layer of paint. Glazes are used on top of one another to build up depth and modify colors in a painting. A glaze must be completely dry before another is applied on top.
Grisaille – A monochromatic oil painting which is often used in underpaintings.
Ground – A coating material, usually white, applied to a support to make it ready for painting.
Hue – The perceived color of an object or a combination of less expensive pigments that closely imitates the mass tone of a more expensive pigment.
Impasto – A style of painting characterized by thick, textured paint application.
Imprimatura – An initial stain of color painted on a ground. It provides a painter with a transparent toned ground, which will allow light falling onto the painting to reflect through the paint layers.
Lean – A term used to describe the low oil content in paints and mediums. Thinning with solvent results in a lower oil content.
Lightfastness – The lightfastness of a paint color or pigment is how permanent it is, or how unaffected it is by light. Gamblin Artist’s oil colors are rated according to the American Society for Testing and Materials (ASTM) LIGHTFASTNESS KEY:
I – Excellent lightfastness
II – Very good lightfastness
III – Fair lightfastness
Mass Tone – The undiluted color of a pigment or a pigmented paint, also known as mass color.
Pigment – Pigment is the substance or powder that makes up the color of a paint. Pigments are either organic (carbon based) or inorganic (mineral based).
Plein Air – A painting done outside rather than in a studio. The term comes from the French en plein air, meaning ‘in the open air’.
Shade – A color mixed with black.
Size – A glue put on a fabric or paper before priming to seal the cellulose and protect it from the oil in the ground and paint. It’s also used to seal wood panels before painting.
Scumbling – A painting technique where a thin or broken layer of color is brushed over another so that patches of the color beneath show through. It can be done with a dry brush, or by removing bits of paint with a cloth.
Support – The actual material or surface on which a painting is created, for example; paper, canvas, panel.
Tint – A tint is any hue (color) that has been mixed with white.
Tone – A color mixed with grey.
Underpainting – The initial stage or first layer of an oil painting commonly executed using a monochrome or dead color as a base for the composition.
Value – The lightness or darkness of a color, rather than the actual color.
Varnish – A final layer that can be applied over a finished painting. A varnish protects a painting from environmental dirt and dust and is removable for cleaning and conservation purposes.
Verdaccio – An Italian name used to describe a muted earth green used for defining tonal values and creating a complete monochromatic underpainting.