Acrylic ground — acrylic dispersion grounds used in place of traditional gesso. They are quite flexible, unlike gesso.
Color Index Name Code
E F G
Gesso — the traditional ground made from hide glue (aka rabbit skin glue), slaked plaster of paris, or white chalk as the pigment.
Imprimatura — a toning of the white ground with a transparent colour, usually done after the artist has transferred a drawing onto the ground and strengthened it with ink (in the Flemish technique).
J K L
Liquin — Liquin is an alkyd medium that speeds the drying of oil paints, and adds transparency. If one is to use it at all, the safest way is to add it to all layers in the painting, but Virgil suggests that the amount added be minimal.
Long paint — The terms ‘long & short’ refer to the consistency of paint squeezed from the tube. If you squeeze paint out of a tube and it comes out as a long, stretchy rope, it’s long. Long paint is, also, called “ropey.”
PVA Size — Poly Vinyl Acetate Size — a neutral pH contemporary size for fabric support, best diluted with distilled water. Recommended by conservation scientists over traditional rabbit skin glue. PVA provides a good size layer that seals the fabric but does not re-absorb atmospheric moisture, swell and shrink like rabbit skin glue does. There are hundreds of different formulae of PVA.
Primer — a synonym for ground, and not to be confused with sizes, imprimaturas, or isolating varnishes
Priming — the act of applying a ground to a support.
Rabbit skin glue — a traditional size for fabric support and panel supports. The size consisted of a hide glue that was melted in a double boiler with a white pigment (powdered chalk, slaked plaster of paris, or gypsum) and applied while still warm. Rabbit skin glue tends to re-absorb atmospheric moisture, swell and shrink. It is a cause of cracking in old oil paintings on canvas. For that reason, conservation scientists recommend using neutral PH PVA size instead.
Short Paint — The terms ‘long & short’ refer to the consistency of paint squeezed from the tube. If you squeeze paint out of a tube and it comes out like thick toothpaste, it’s short.
Sizing — a thin application of a substance that will mitigate the absorbency of canvas or wood to prevent oil from soaking into the cellulose fibers and initiating the rotting of them. See PVA and Rabbit Skin Glue.
Turpenoid — a.k.a. odorless mineral spirits (OMS,) a mild solvent that is sometimes used in oil painting mediums in combination with linseed oil or stand oil, and for rinsing paint brushes. Note that the absence of detectable odor is not to be interpreted to mean that therefore it’s without potential health consequences of inhaling its vapors or ingesting it.
Turpenoid Natural — a mixture of a citrus peel solvent and linseed oil. Turpenoid Natural has such powerful solvent action that it will eat through oil paint on paintings hundreds of years old, which makes it a good choice for cleaning brushes that have dried paint on them, but not a good choice for thinning oil paints or using as a painting medium or medium ingredient.