| accelerated weathering |
The process of evaluating products to obtain information on durability and performance more quickly than by in-service testing. |
| acrylic paint |
Paint manufactured with acrylic resins as the main binder, which may be of latex or solvent-borne type. |
| additive |
Any substance, added in small quantities to a coating material, to improve or modify one or more properties. |
| aeration |
Incorporation of bubbles of air in paint during stirring, shaking or application. |
| ageing |
The irreversible changes in the properties of a film, which occur with the passage of time. |
| air drying |
The formation of a solid paint film from a liquid paint film under natural ambient conditions. |
| application rate |
The quantity of a coating material that is required to produce, under defined working conditions, a dry film of a given thickness on unit area. |
| artificial weathering |
The testing of coatings in which ageing in induced by exposure to simulated conditions such as ultraviolet radiation or moisture. |
| binder |
The non-volatile part of the medium that forms the film. |
| bleeding |
The process of diffusion of a coloured substance into and through a film from beneath, thus producing an undesirable staining or colour change. |
| blistering |
The convex deformation in the film, arising from local detachment of one or more of the constituent coats. |
| breathing |
The passage of vapour through a paint film without the paint film exhibiting blistering, cracking or peeling. |
| brushability |
The ease with which a paint can be uniformly applied with a paintbrush. |
| coat |
A continuous layer of a coating material resulting from a single application |
| coalescing agent |
Additive to a coating material based on a polymer dispersion to facilitate film formation by the temporary softening of the polymer particles. |
| cracking |
Formation of breaks in a paint film, which expose its substrate. |
| curing |
The process of condensation or polymerisation of paint by heat, radiation or chemical means, resulting in the full development of desirable properties. |
| defect |
A failure of a coating system to achieve one or more of its intended functions. |
| dirt retention |
The tendency of a dry film to attract to the surface soiling material that cannot be removed by simple cleaning. |
| discolouration |
Any change in the colour exhibited by a paint film as a result of exposure, including that due to chalking, dirt collection and biological organisms such as mould. |
| durability |
The degree to which films of paint and paint materials withstand the destructive effect of the service conditions to which they are subjected. |
| fading |
The loss of colour of one or more of the colour pigments within the film of a coating material. |
| film |
A continuous layer resulting from the application of one or more coats to a substrate. |
| finish coat, finishing |
The final coat of a coating system. |
| flaking |
The complete detachment of pieces of paint film from the underlying surface or substrate. |
| flat (finish) |
A surface with a specular gloss reading not greater than 5 gloss units when the specular direction is 60 degrees. |
| flow |
The ability of a paint to spread to uniform thickness after application. |
| full-gloss (finish) |
A surface with a specular gloss reading above 85 gloss units when the specular direction is 60 degrees. |
| full coat |
A paint coating that has been applied in accordance with the manufacturer's recommended wet film thickness. |
| fungicidal growth |
A coating material that discourages the growth of surface moulds on the dry film. This property is normally conferred by the use of special additives, although certain pigments may themselves contribute to the fungicidal property of the paint. |
| fungal growth |
The appearance of non-photosynthesising micro-organisms consisting of spores, hyphae, or both, which may be characterized by filamented branched structures. |
| gloss |
The optical property of a surface, characterized by its ability to reflect light specularly. |
| gloss (finish) |
A surface with a specular gloss reading above 50 gloss units but not exceeding 85 gloss units when the specular direction is 60 degrees. |
| hardness (of a film) |
The ability of a dried film to resist indentation or penetration of a solid object. |
| low-gloss (finish) |
A surface with a specular gloss reading above 5 gloss units but not exceeding 20 gloss units when the specular direction is 60 degrees. |
| mineral turpentine |
A blend of aliphatic and aromatic hydrocarbons commonly used as a thinner for alkyd paints and coatings. |
| mould growth |
The presence of dark brown to black spots on a paint film resulting from microbiological action of moulds, fungus or algae. These microbiological activities may cause discolouration of the paint system. |
| Newtonian liquid |
A liquid whose viscosity remains constant at constant temperature, irrespective of the rate of shear. |
| opacity |
The ability of a paint to obliterate the colour difference of a substrate. |
| paint |
A product in liquid form, which, when applied to a surface, forms a dry film having protective, decorative or other specific technical properties. |
| paint remover |
A compound that softens paint or varnish and permits the softened material to be scraped off, or hosed off with water. |
| peeling |
Localized loss of adhesion between the surface film and underlying components of a paint system without complete detachment of loose fragments of the film. |
| plasticizer |
A substance added to a coating material to make the dry film more flexible. |
| popping |
A small bubble-like defect in a paint film resulting from the expansion or hydration of extraneous material in the plaster substrate; also known as blowing. |
| primer coat, prime coat |
The first coat of a painting system that helps bind subsequent coats to the substrate and which may inhibit its detorioration. |
| resin |
A natural or synthetic organic material used to bind pigments together, and to the substrate. |
| sealant |
A permanently flexible material used to fill expansion joints and gaps in buildings so as to provide a weatherproof seal. |
| sealer |
A product used to seal substrates to prevent materials from bleeding through to the surface, to prevent reaction of the substrate with incompatible top coats or to prevent undue absorption of the following coat into the substrate. |
| semi-gloss (finish) |
A surface with a specular gloss reading above 20 gloss units but not exceeding 50 gloss units when the specular direction is 60 degrees. |
| sheen |
A property of a finish that appears to posses gloss when seen at glancing angles to the surface, but which when viewed at an angle normal to the surface, appears flat. |
| solvent |
A single liquid or blends of liquids, volatile under specified drying conditions, in which the binder is completely soluble. |
| substrate |
The surface to which the coating material is applied or is to be applied. |
| sugar soap |
A product that, after mixing with water, gives an alkaline solution used for washing down sound paintwork before repainting. |
| texture |
The roughness or irregularity of a surface. |
| thickening |
The increase in the consistency of a coating material but not to the extent as to render it unsuitable. |
| thickening agent |
Additive that increases the viscosity of the liquid coating material. |
| thinner |
A volatile liquid, single or blended, added to a product to lower the viscosity. |
| touch-dry |
The stage during the drying or curing process when the paint film no longer feels sticky when lightly touched. |
| undercoat |
An intermediate coat formulated to prepare a primed surface or other prepared surface for the finishing coat. |
| varnish |
A coating material, which, when applied to a substrate forms a solid, transparent film having protective, decorative or specific technical properties. |
| viscosity |
The quantifiable relationship between applied shear force and shear rate for a fluid. |
| volatile organic compound (VOC) |
Fundamentally, any organic liquid and/or solid that evaporates spontaneously at the prevailing temperature and pressure of the atmosphere with which it is in contact. |
| volatile organic compound content (VOCC) |
Mass of the volatile organic compounds present in a coating material, as determined under specified conditions. |
| washability or scrubbability |
The ease with which dust, soiling and surface stains can be removed by washing from a dry film of a coating material without detriment to its specified properties. |
| weathering |
The exposure of paint films to the weather, to determine their behaviour to natural elements and pollution. |
