Viscosity
A liquid’s resistance to flow. Application method, temperature and thinning ratio can affect viscosity.
VOC (Volatile Organic Compound)
A general term for organic compounds that can evaporate under normal use or drying conditions. Check the product’s current technical documentation for its VOC value.

Flaking
Separation of the paint film from the surface in pieces due to loss of adhesion or flexibility.
Vehicle
The liquid phase in which pigments and other solids are dispersed; it may consist of a binder and thinning components such as water or solvent.
Chalking
Formation of a fine, easily wiped-off powder on a painted surface as the binder deteriorates under weathering.
Thermoplastic
A polymer structure that softens when heated and hardens again when cooled.
Thermoset
A crosslinked polymer structure that, once cured, does not melt or return to its original fluid state when reheated.
Titanium dioxide (TiO₂)
An inorganic pigment widely used in paints and coatings for its high whiteness and hiding power.
Dust-free drying
The drying stage at which airborne dust will no longer adhere to the surface of a paint, primer or varnish film.
Efflorescence
White deposits formed on walls, brick, render or concrete when moisture carries soluble salts to the surface.
Scale
An oxide layer formed on steel during hot working that no longer has metallic properties.
Salt spray test
An accelerated laboratory test used to compare the corrosion resistance of coated metal specimens in a controlled salt fog environment.

Sagging
The downward flow of a wet paint film on a vertical surface under gravity, creating thick streaks.
Semi-gloss
A surface finish with a level of light reflection between matt and gloss.
Hardener
The second component in a two-component system, which reacts with the binder to enable curing.
Hardness
The resistance of a dry paint film to mechanical effects such as scratching, indentation or abrasion.
Sherardised surface
A steel surface coated with a zinc–iron diffusion layer by treatment with zinc dust at a controlled temperature.
Silicone cratering
Circular depressions and openings caused when silicone, oil or similar surface contaminants repel the paint.
Fading
The gradual loss of colour strength due to light, heat, chemicals or weathering.
Peeling
Separation of the paint film from the surface in strips or sheets as a result of loss of adhesion.
Stability
The ability of a product to retain its essential physical and chemical properties during storage or use.
Water resistance
The ability of a dry coating film to retain its appearance, adhesion and protective properties when exposed to water.
Blushing
A cloudy appearance involving loss of gloss and clarity, caused by moisture, rapid solvent evaporation or incompatible components.
Straining
The removal of foreign particles or lumps from paint using a suitable filter.

Rust
A general term for iron oxide and hydroxide products formed by corrosion on iron and steel surfaces.
Pigment
Fine, generally insoluble solid particles dispersed in a binder to provide colour, hiding power or specific performance properties.
Pigment floating
Separation of different pigments at the surface of a wet film due to differences in wetting or density, causing uneven colour.
Plasticiser
An additive incorporated into a formulation to increase film flexibility and reduce brittleness.
Polymerisation
The chemical process by which small molecules called monomers form long-chain or network polymers.
Orange peel
A wavy texture resembling orange peel on a dry film surface, caused by inadequate flow and levelling.
PVA (Polyvinyl Acetate)
A synthetic polymer that can be used as a binder or film former in paints, adhesives and various industrial applications.
PVC (Pigment Volume Concentration)
The volume of pigments and fillers as a proportion of the total non-volatile solid volume in a coating, expressed as a percentage.

Sanding
Mechanical preparation using an abrasive material to clean, roughen or smooth a surface.

Wet-on-wet
Application of a subsequent coat within a specified interval before the first coat has fully dried.
Flow
The ability of a wet coating to reduce application marks and form a smooth, uniform film.
Washability
The capacity of a dry paint film to retain its appearance and integrity during cleaning.
Density
The mass of a substance per unit volume, generally expressed in kilograms per litre for paint products.

Application viscosity
The range of flow resistance that allows a product to be applied correctly using the selected brush, roller or spray equipment.

Micron
A unit of length equal to one thousandth of a millimetre, used in the coatings industry to specify wet or dry film thickness.

Oxidation
A chemical reaction involving electron transfer between a substance and oxygen or another oxidising agent.
Oxidative drying
The crosslinking and hardening of certain binders through reaction with oxygen in the air.
Opacity
The degree to which a coating prevents the underlying surface or previous colour from showing through.

Hiding power
The ability of a paint to conceal the colour and pattern of the underlying surface at a given film thickness.

Resin
A natural or synthetic polymer-based component that acts as the binder in a coating, holding pigments together and providing adhesion and the film’s fundamental performance properties.
Colour retention
The ability of a coating to retain its original colour under exposure to light, heat, weather or chemicals.

Blistering
Dome-shaped raised areas in a paint film caused by moisture, trapped solvent, osmotic pressure or loss of adhesion.
Bleeding
Discolouration caused when colourants or stains in an underlying coat migrate into the topcoat.
Coating
A film-forming material or layer system applied to a surface to provide protection, decoration or a functional property.
Catalyst
A substance that affects the rate of a chemical reaction and is essentially not consumed by the reaction.
Brittleness
The tendency of a dry film to crack or crumble during bending, impact or elongation.
Consistency (viscosity)
A paint’s resistance to flow; higher-viscosity products flow more slowly.
Component
Each separate constituent of a multi-component product system.
Conical mandrel
A conical test device used to assess the bending and flexibility performance of a coating film.
Corrosion
Deterioration of a metal’s properties through chemical or electrochemical reactions with its environment.
Crater
A circular depression with raised edges in a wet film, caused by air, gas or surface contamination.
Abrasive blasting
Directing abrasive material at a surface under pressure to remove rust, scale and old coatings and establish a suitable surface profile.
Dry spray
A rough, poorly coalesced film formed when sprayed paint droplets lose too much solvent before reaching the surface.
Mould
A general term for fungal growth that can develop on surfaces under moist conditions with suitable nutrients.
Curing
The process by which a coating reaches its intended final hardness and performance through physical or chemical mechanisms.

Pinholing
Tiny, pin-sized openings formed as trapped air, moisture or solvent escapes from the film.
Thinner
Water or a compatible solvent blend used to adjust paint application viscosity; the type and ratio are specified in the technical data sheet.

Volume solids
The proportion of the product’s total volume occupied by the pigments, fillers and binder remaining in the film after volatile components have evaporated.
Mill scale
A dense oxide layer formed on steel during hot rolling or heat treatment.
Air-drying paint
A paint system that dries under normal ambient conditions through solvent/water evaporation, oxidation or both mechanisms.
Airless spraying
A method of applying paint by atomising it through a nozzle under high fluid pressure without mixing it with compressed air.
Accelerator
A substance added to a formulation to promote the initiation or increase the rate of a reaction.

Galvanised surface
A steel surface coated with zinc or a zinc alloy to improve corrosion resistance.
Extender pigment
A mineral pigment used to adjust coating properties such as rheology, mattness, hardness or cost.

Film formation
The formation of a continuous coating layer as water or solvent evaporates and binder particles coalesce or react.
Flash-off
The waiting period after wet application that allows volatile components to evaporate in a controlled manner before the next coat or baking.
Wet-on-wet primer
A primer that can be topcoated before fully curing and subsequently cures together with the system.
Flocculation
The formation of larger clusters as pigment particles associate through weak bonds.

Elasticity
The ability of a dry film to accommodate deformation without cracking or losing adhesion.
Electrostatic application
A spray method in which electrically charged paint particles are directed towards a grounded workpiece.
Impregnation
The penetration of a low-viscosity product into a porous surface to fill voids and prepare it for subsequent treatment.
Emulsion
The dispersion of one of two mutually insoluble liquids as fine droplets in the other phase with the aid of an emulsifier.
Enamel
A type of paint generally designed to form a smooth, durable, decorative finishing film, available in different gloss levels.

Dip coating
An application method in which a component is immersed in coating material and withdrawn in a controlled manner.
Impact test
A test assessing a coating’s resistance to cracking and detachment, and its adhesion under sudden mechanical deformation.
Durability
The degree to which a coating retains its properties throughout use when exposed to weather, chemicals, mechanical stress and other deteriorating influences.
Dispersion (suspension)
The distribution of fine solid particles as uniformly as possible throughout a liquid phase.

Cross-cut test
A test method that comparatively assesses a dry coating’s adhesion to the substrate using a standard cut pattern and adhesive tape.

Cracking
Linear fractures in a dry paint film caused by stress, ageing, excessive thickness or incompatibility.
Dew point
The temperature at which water vapour in the air begins to condense on a surface. It should be assessed together with the surface temperature before application.
Scratch resistance
The resistance of a dry film to marking and damage under sharp or abrasive action.

Whitewash
A decorative coating traditionally made from lime and water, mainly used on mineral surfaces.
Binder
The essential component that holds pigments together and enables the coating to adhere to the surface and form a continuous film.
Fisheye
A circular opening defect formed when oil, silicone or similar surface contaminants repel wet paint.
White rust
A white corrosion product that can form on zinc-coated surfaces under moist conditions with inadequate ventilation.
Whitening
Lightening of a coating’s colour as a result of exposure to light, weather or chemicals.
Paint
A coating material formulated to form a protective, decorative or functional film on the surface to which it is applied.
Paint defect
An unwanted appearance or performance problem in a film arising from preparation, application, drying, curing or service conditions.
Bronzing
An appearance defect in which certain pigments produce an optical metallic or bronze-coloured sheen on the surface.

Adhesion
The ability of a dry coating film to adhere to the substrate or underlying coating.
Airless spraying
Application of wet paint by atomising it through a spray gun under high pressure without mixing it with compressed air.
Acrylic
A family of synthetic polymers derived from acrylic or methacrylic monomers and used in coatings for properties such as colour retention and weather resistance.
Acrylic paint
A paint system whose film-forming binder is an acrylic polymer or copolymer.
Acrylic resin
An acrylic binder used in coating formulations to provide gloss and colour retention, hardness, adhesion or exterior performance.
Flash point
The lowest temperature at which a liquid’s vapours can ignite momentarily in the presence of an ignition source under specified test conditions.
Alkali resistance
The ability of a dry coating to retain its appearance and integrity when exposed to alkaline substances or alkaline surface conditions.
Alkyd
A family of resins produced from polyols and polybasic acids modified with fatty acids, used as binders in paints, varnishes and primers.
Flash rusting
A thin layer of surface rust that forms rapidly on cleaned steel or during water-based application.
Anticorrosive paint
A primer or coating system formulated to reduce the rate of corrosion on a metal surface and extend its service life.
Acid resistance
The degree to which a dry paint or varnish film retains its properties when exposed to specified acids.