Undercoat:-
A highly pigmented coating applied after a primer to give a thick opaque low gloss film. It provides covering power and build. It can also serve the purpose of a filler coat that can be easily abraded to produce an even substrate for the topcoat. See also sealer, size, filler, and bonding liquid.

Varnish:-
A transparent coating material based essentially on resins and/or drying oil and solvent.

Vehicle:-
The liquid portion of a coating, in which the pigment is dispersed; see medium

Viscosity:-
The internal resistance to flow possessed by a fluid; the rate of flow of a material when a force is applied to it . There are various methods of reading this depending upon the nature of the substance. Eg: Ford cup B4 viscosity is reported in seconds.

Volatile content:-
The percentage of the mass of a coating which is lost when the coating has dried completely

Volatile Organic Compound (VOC):-
Fundamentally any organic liquid or solid that vaporises spontaneously at the prevailing temperature and pressure of the surrounding atmosphere.

Volatile Organic Compound Content (VOCC):-
The mass of the volatile organic compounds present in a coating material as determined under specified conditions.

Wet Film Thickness (WFT):-
A paint essentially consists of 3 components. Pigment Binder and solvent. The solvent being present to allow viscosity adjustment for correct application the pigment and binder form the real surface coating. During and after application the solvent evaporates and thereafter takes no further part in the process. As the dry component is the true paint its durability and functionality can be dictated by the thickness of this film which, when measured, is termed the "Dry Film Thickness". Control of wet film thickness during application is essential to ensure the correct Dry film. Control of the wet film thickness during application also ensures that excessive paint is not used and so ensuring optimum & cost effective results. See DFT.

White spirit:-
A petroleum distillate having a wide boiling range; a mixture of aliphatic and aromatic hydrocarbons used as a solvent. See Mineral spirit, Turpentine substitute.

Wrinkling:-
Wrinkles in film on drying. Causes - wrong driers, too thick a coat. Film detaches and crumples when second coat applied. See 'Paint defects' in 'Helpline' for more information.

Wrinkle Finish:-
Coating which upon drying gives a wrinkled appearance. One favoured for office machines.