Glossary of Paint

& Painting Terms

Barrier Coat
A coat used to isolate subsequent coats from the pre-ceding coats of substrate to prevent adverse physical or chemical interaction.

The first decorative coat of a multicoat coating system.

The non-volatile portion of the vehicle of a coating ma-terial that binds the pigment particles together and the film as a whole to its substrate.

Biocidal Wash
A solution containing fungicides and/or algicides that is applied to a substrate before painting to kill existing fungal or algal contamination or to prevent their devel-opment.

The presence of particles of gel, flocculated material or foreign matter in a coating material.

A viscous liquid or a solid, consisting essentially hy-drocarbons and their derivatives, which is soluble in aliphatic solvents and is substantially non-volatile and softens gradually when heated.

The total loss of colour of a coating usually as a result of weathering or chemical attack.

Undercoat staining through the topcoat. 

Formation of dome-shaped projections in paints or varnish films resulting from local loss of adhesion and liftingof the film from the underlying surface.



Undesirable adhesion between two painted surfaces or between paint and weather stripping. The paint sticks to itself or to the weather stripping when a window or door is opened and usually leaves bare patches of substrate.


A deposit resembling the bloom on a grape that some-times forms on the gloss film of a coating, causing loss of gloss and dulling of colour.


A milky opalescence that sometimes develops as a film of lacquer dries and is due to the deposition of mois-ture from the air and/or precipitation of one or more of the solid constituents of the lacquer; usually confined to lacquers that dry solely by evaporation of solvent.


The thickness or viscosity of a fluid.


Mixing paint by pouring from one container to another several times to ensure thorough mixing.


The ability of a paint film to permit the passage of moisture vapor without causing blistering, cracking, or peeling.+


The covering over of an unfilled gap such as a crack or corner with the film of a coating material. This introduces a weakness in the coat that may lead to an

eventual cracking of the dried paint.

Broken Colour

The general multi-coloured effect brought about by the automatic merging of wet paints of various colours or by manipulation that produces random effects.

Brush Marks

Ridges remaining in a dry paint film after brush application.


The appearance of temporary or permanent bubbles of air or solvent vapour or both in the applied film.


Thickness of dried paint film.

Burning Off

The removal of paint by a process in which the paint is softened by heat, such as from a flame, and then scraped off while still soft.


Shiny or lustrous spots on a paint surface caused by rubbing.



A substance that increases the rate of a chemical reaction, but that remains chemically unchanged at the end of the reaction.

Caulk Failure

Formation of a powder on the surface of a paint film caused by disintegration of the binder during weather-ing. Can be affected by the choice of pigment or binder.


The formation of a loose powder or the surface of paint after exposure to the elements.


A state of dry intermediate between surfaces dry and hard dry.


The removal of paint and surface contaminants from a substrate by means of impact from a sharpened tool.


The recession of a wet paint film from a surface leaving small areas uncoated.



A continuous layer of a coating material that results from a single application.

Coating Material

A film forming material used to cover a substrate for protective or decorative purposes.


Coating System

A coating material or sequence of coating materials applied in a specified number of coats to impart protective, decorative or other properties to a substrate.


The forces that bind together into a coherent whole the particles of film..


A concentrated agent that may be added to paints to make a range of colours.


Non-fading in prolonged exposure to light.

Compatibility of a Product with the Substrate

The ability of a coating material applied to a substrate to give a dry adherent film without causing undesirable effects either on the properties of the product or the nature of the substrate.


The apparent viscosity of a paint under application of a shearing force.


The product obtained from polymerisation of two different monomers.

Cracking or Flaking

The type of paint failure characterised by breaks in irregular lines wide enough to expose the underlying surface.


Residual effect of burst bubbles. (See also cissing.)


Varnish defect in which poor adhesion of varnish to surface in some spots causes it to gather up in globs.


The formation of minute criss-cross cracks on the surface of a paint film.


The formation of wide criss-cross cracks in a paint film.



The process of condensation or polymerisation of a material by heat or chemical means resulting in the full development of the desired properties.


Curtain Coating

Curtain coating is a process that creates an uninterrupted curtain of fluid that falls onto a substrate.



Careful painting of an edge such as wall color at the ceiling line or at the edge of woodwork.



Removing, by rubbing with fine abrasive paper, any small particles of foreign matter that stand proud on the surface of a paint film.


The removal from a surface, prior to painting, of mineral oils, greases and similar substances by means of a solvent, such as trichloroethylene, or an emulsifying agent.


The removal of mill scale or laminated rust from steel or other ferrous substrates.


Any change in colour of an exposed film caused by chalking, dirt collection or fading, darkening or tonal changes in the original colour.


The resistance to the brush encountered when applying a coating material.


Dry Film Thickness

The arithmetic means of a series of dry film thickness measurements.


The change of a coating material from the liquid to the solid state, due to the evaporation of solvent or physio chemical reactions of the binding medium or a combination of these processes.


A measure of the ability of a coating system to with-stand the environment in service.



A deposit of salts that remain on the surface of masonry, brick or plaster when water has evaporated.

Eggshell Finish

A coated surface that exhibits diffuse reflectance, which is intermediate between a semigloss finish and a matt finish.


A macro-molecular material that, after substantial deformation by a weak stress at room temperature returns rapidly to its initial shape and dimensions when the stress is removed.

Electrostatic Spraying

A method of spraying in which an electrostatic potential difference is applied between the article to be coated and the atomised coating material particles whereby the latter are attracted to and deposited on it with minimal loss of overspray.



A stable suspension of fine particles or globules of one liquid in another.

Emulsion Paint

A coating material in which the medium is a dispersion of an organic binder in water.

Enamel Paint

Pigmented organic polymeric binders that simulate the appearance, flow, smoothness and gloss of fused inorganic coatings.

Epoxy Paint

A coating material based on an epoxy resin.

Epoxy Resin

A synthetic resin containing epoxide groups and in which the final polymer is formed because of a reaction taking place substantially at the epoxide groups.

More coming soon...