Download the guide as a PDF: Glossary of Terms
A volatile solvent, excellent in mixtures (such as mixing with oil and water).
Resins resulting from the polymerization of esters of acrylic and methacrylic acids. Most acrylics require strong solvents, although some may be formulated using aromatic hydrocarbons without oxygenated solvents.
Any chemical added in small amounts to a coating to achieve specific properties (mar resistance, slip, etc.)
A compromise between conventional spray and airless spray methods, air-assisted spray technology uses a small amount of atomizing air with higher fluid pressures to allow for good film appearance with good transfer efficiency.
Air Dry Coating
A coating formulation that dries after application without the use of heat.
Latent solvents for many materials. Characterized by the presence of a hydroxyl group. Capable of strong hydrogen bonding. Oxygenated solvents.
Synthetic resins formed by the condensation of polyhydric alcohols and polybasic acids. They may be regarded as complex esters. Most commonly made from glycerin and phthalic anhydride. Solvent requirements vary, ranging from strong aromatic hydrocarbons to low solvency aliphatic hydrocarbons.
Paint made with synthetic resins which have good retention of color and flexibility. Also oil-modified alkyd which contains a drying oil as part of its makeup.
Alkyd / Urea
Blend of resins most commonly used in conversion coatings. Releases characteristic formaldehyde odor.
Coatings intended for on-site application to interior or exterior surfaces of residential, commercial, institutional, or industrial buildings. These finishes are applied at ambient temperatures and dry without being heated. Also called trade sales coatings.
Characterized by unsaturated, six carbon benzene ring structures. Hydrocarbon solvents which contain more than 50% aromatic compounds are designated as aromatic hydrocarbon solvents. Strongest of the hydrocarbon solvents. Strongest odor.
Auto Ignition Point
Temperature at which vapor from volatile material self-combusts.
A coating which requires heat for curing and the development of desired properties.
The solvent blend which is used in the preparation of a coating for dissolving the resin and dispersing the pigments.
Small, rounded variations in the surface color in opaque films caused by eddies and currents created from the evaporation of solvents.
Binder / Backbone
The name given to the blend of resins in a coating which gives a film most of its properties.
Film defect which occurs when volatiles leaving a film are trapped and expand inside the film.
A clouding of the finish material coming in contact with dirt or moisture.
A milky appearance in a film created when airborne moisture condenses in a film cooled by evaporating solvents.
The percentage of incident light reflected by an object. A perfectly white material has 100% brilliance while an absolute black material has zero brilliance.
The apparent depth a coating gives to its substrate.
UV-resistant resin with characteristics of a lacquer. Used where light stability and good flow are needed.
The highly reactive chemical which when added to conversion coatings initiates chemical bonding.
The colors of the spectrum, namely: red, orange, yellow, green, blue, violet. These six colors are related to each other as follows:
|Color||Approximate wave length: (Millimicrons)||Color Classification||Obtained by mixing|
|Red||610 to 700||Primary||---|
|Yellow||570 to 590||Primary||---|
|Blue||460 to 500||Primary||---|
|Orange||590 to 610||Secondary||Red and Yellow|
|Green||500 to 570||Secondary||Yellow and Blue|
|Violet||400 to 460||Secondary||Blue and Red|
|Citron||---||Tertiary||Orange and Green|
|Olive||---||Tertiary||Green and Violet|
|Russet||---||Tertiary||Violet and Orange|
A generic term for paints, lacquers, enamels, etc. Also a liquid composition which is converted to a solid protective, decorative, or functional adherent film after application as a thin layer.
The cracks formed from the expansion and contraction which results from hot and cold cycles.
The quality by which bodies have a different appearance, independently of their form, depending on the effect of different wavelengths on the retina of the eye.
The tendency for certain pigments in a coating to rise to the surface in unagitated material.
A computerized meter which digitally “fingerprints” a specific opaque color according to its characteristic wavelengths of light.
Red and green, blue and orange, yellow and violet are complementary pairs of colors. Complementary colors from a given pair are always harmonious when used near each other as separate colors in the proper relative amounts.
A traditional spray finishing method that gives excellent atomization of the paint at the expense of lower transfer efficiency.
A blend of two or more solvents, none of which will dissolve the resin by itself, but which will act as a true solvent for the material when used together. Each cosolvent must evaporate at about the same rate, otherwise resin precipitation will occur as drying proceeds.
The process of chemically bonding or crosslinking the resins in a film.
Mileage, usually given in square feet per gallon for a given dry film thickness.
The “pulling away” from surface contamination which forms a crater-like deformation in the film.
Term often used in place of cold checking.
A blend of highly refined micro-crystalline fossil-origin waxes used to revive and protect valuable furniture, leather, paintings, metals, marble, onyx, ivory, etc. Freshens colors and imparts a soft sheen.
Materials used to thin paints, either to make them more workable or to give them a consistency which is suited to a particular technique. In theory a diluent is only a temporary addition to paint and should evaporate evenly and completely during drying, leaving the original composition of the paint unchanged, and producing no lasting odor or stain.
The wetting-out of fine pigment particles with coating material.
The temperature range over which a mixture of liquids will distill. The range is narrow for most oxygenated solvents, but may be quite wide for hydrocarbons. ASTM Method D-86 is used for hydrocarbons.
Distinctness of Image (DOI)
The degree of distortion in a reflected image on the surface of a high gloss coating.
Resins which contain epoxy groups (also known as oxirane groups). Most commonly made from epichlorohydrin and bisphenol A. May be liquid or solid, depending on molecular weight. Uses mixtures of alcohols, ketones and hydrocarbons.
A topcoat which is characterized by its ability to form a smooth surface. May also refer to a thermosetting or baking finish.
A class of active solvents formed from organic acids and alcohols by the elimination of water. Oxygenated solvents.
Ethanol (or ethyl alcohol)
A volatile solvent widely used in industry but of relatively minor importance to artists. It is the solvent for shellac and a few other resins, a diluent for some of the fixatives, and a mildly active wetting agent.
The relationship of evaporation out of a film as a function of time produced by a blend of solvents in a coating.
A measure of the length of time required for a given amount of a solvent to evaporate. Solvents are generally characterized as fast, medium or slow evaporating. Most commonly measured using the Shell Thin-Film Evapometer, ASTM Method D-3539.
Highly pigmented material used to fill the open pores of wood before the application of a coating.
A type of crater but is usually larger and sometimes contains a particle of contamination.
The initial evaporation of solvent from an applied film.
The temperature at which a vapor from a volatile material will combust if externally ignited.
The elasticity a coating needs to overcome physical deformation.
The ability of a material to level-out over surface defects.
A measure of the polar character of a solvent. Values are between zero and one, the higher the value, the more polar the solvent. Hydrocarbons have very low polarity, while oxygenated solvents have higher polarity.
A white fluid or plastic coating material made by mixing chalk or whiting with a glue solution or, occasionally, casein. Early gesso was made from parchment glue and slaked plaster of Paris; modern gesso uses rabbitskin glue and precipitated chalk or whiting. The word gesso is Italian, and derives from gypsum, from which plaster of Paris is made. However manufacturers in recent years have applied the term to polymer primers, which are entirely different from gesso in composition and cannot be used as a substitute for it.
To cover with gold or a golden finish, whether by applying gold leaf, by electroplating or metal spraying or applying gold paint.
The degree to which a coating is able to reflect an image.
Prepared from alcohols and ethylene or propylene oxide. Contain both ether groups and hydroxyl groups, thereby possessing the characteristics of both. Oxygenated solvents.
A coating designed for use on large exterior surfaces of a building. Generally of lower gloss than the coating used on trim areas. May be either water based or oil based.
The predominate wavelength reflected by a colored material which determines its position in the chromatic scale.
A finishing spray method that uses a high volume of air at a low pressure to atomize paint into a pattern of low speed particles, thus producing better transfer efficiency than conventional air.
Compounds composed exclusively of hydrogen and carbon.
The adhesion a topcoat has to a previous coat.
Refers to how deep a black coating looks when compared to other black coatings.
A class of active, strong solvents characterized by a carbonyl group. Oxygenated solvents.
These resins are added to all types of coatings formulations to improve properties such as gloss, film hardness, flow and UV stability. In addition, thanks to their excellent pigment-wetting properties and broad compatibility with other resins, they can be used to make all-purpose pigment preparations.
A coating based on a thermoplastic polymer dissolved in organic solvent and which dries primarily by solvent evaporation. The coating can be redissolved in its’ original solvent blend. The most common polymers used in lacquers are nitrocellulose, vinyl resins and acrylic resins.
A solvent which is not a true solvent for the material being dissolved, but which will act as a solvent in the presence of an active solvent. Alcohols are the most common latent solvents.
A stable dispersion of a polymer in a continuous liquid medium, usually water. Prepared by emulsion polymerization.
A coating which uses a latex as the principal binder. Widely used for interior and exterior house paints. Contains only small amounts of solvents, usually glycols, glycol ethers and glycol ether esters.
The wrinkle or seedy look which occurs from the stripping effect a topcoat with active solvents has on a cured bottomcoat.
Ability of the dry film to resist scratching.
A full strength color. The hue of a color not toned with white or black.
A way of determining solvent resistance and extent of cure by rubbing the surface of a coating with a cloth laden with methyl ethyl ketone.
The characteristic of a color which enables it to appear differently under various types of lighting.
1/1,000th of an inch.
The number of pieces or the square feet which are able to be coated by 1 gallon of material at a specific coating depth in mils.
A small reactive molecule which chemically bonds to form a polymer.
Completely saturated hydrocarbons characterized by ring structures. Intermediate solvency between paraffin and aromatic hydrocarbons. Intermediate odor. Also known as cycloparaffins.
A resin used in lacquers for clarity, quickness of dry and repairability.
A non-grain raising stain used to give uniformity and transparency to the color of a substrate.
Nonaqueous Dispersion (NAD)
The solvent analog of a latex: a dispersion of a polymer in a volatile organic liquid which is not a solvent for the polymer. Low-solvency aliphatic hydrocarbons are the most commonly used solvents.
Paint that contains a drying oil as the sole film-forming ingredient. Linseed oil is most commonly used for this purpose. Aliphatic hydrocarbons are used in small amounts as the solvent.
A solution of oxidizing resin dissolved in hydrocarbon solvent.
The slight “bumpy” appearance a sprayed surface has when the coating does not have enough flow.
The term that refers to any compound that contains carbon atoms.
The atomized spray material which misses the desired substrate and lands on an undesirable area.
General designation of those solvents which contain oxygen in addition to carbon and hydrogen.
The stain applied to blend in off-color regions of wood.
Any pigmented liquid designed for application to a substrate in a thin layer which is converted to an opaque solid film after application. Used for protection, decoration or identification, or to serve some functional purpose such as the filling or concealing of surface irregularities, the modification of light and heat radiation characteristics, etc.
Completely saturated hydrocarbons characterized by chain structure. Poorest solvency of the hydrocarbon solvents. Least odor.
A tint. A masstone to which white has been added.
A thin layer or corrosion, usually brown or green, that appears on copper or copper alloys, such as bronze, as a result of natural or artificial oxidization. In general, a patina is the sheen produced by age and use on any antique surface.
The tendency of a material to pull away from the center of a substrate and gather at the sharp edges.
A finely divided, colored substance which imparts its color effect to another material either when mixed intimately with it or when applied over its surface in a thin layer. When a pigment is mixed or ground in a liquid vehicle to form a paint, it does not dissolve but remains dispersed or suspended in the liquid.
The amount of dry pigment in a coating.
Pigment to Binder Ratio
The amount of dry pigment compared to the amount of resin solids.
A surface defect with the appearance of a blister that “popped” but did not flow out and appears as a small hole on the film.
A special type of alkyd resins, prepared from dicarboxylic acids and dihydroxy alcohols.
A large molecule which is formed by chemically bonding monomers. Many times they can be further reacted to form larger polymers.
Red, yellow and blue.
First complete coat of paint applied to a surface. Designed to provide adequate adhesion to new surfaces. The type of primer varies with the surface, its condition, and the total painting system to be used.
The migration of solvent and pigment out of the pores of wood after stain or filler has been applied.
The length of time in which a material is still usable after catalyzation.
The ability of a recently cured coating to resist the imprint of an applied force.
The ability to apply a fresh coat of material over a cured dry coat without lifting or loss of adhesion.
Relative Evaporation Rate
The evaporation rate of a solvent compared to a standard, usually n-butyl acetate, with the rate of n-butyl acetate set equal to 1.00. Solvents which evaporate faster than n-butyl acetate have a relative evaporation rate greater than one. Those which evaporate more slowly have a relative evaporation rate less than one.
The ability to physically remove and repair defects from a coating’s surface.
The term which is used to describe the flow, viscosity and thixotrophy of a material.
The ability to easily rub or polish a coating without leaving surface defects or haze.
A shear-related surface defect a coating forms when it is transferred from a roll applicator to the substrate.
Areas of uneven coating produced by flow of excessively thick layers of wet material.
The ease at which a coating can be sanded without dragging or gumming the sanding medium.
The percentage of reflected light which is colored.
A coating which slightly raises the wood grain fiber and seals the wood grain fiber and seals the wood. Upon sanding it leaves a smooth surface and provides build.
Orange, green and violet. Mixtures of primary colors.
A color toned with black or with a complementary color having some degree of dulling effect.
The period of time during which a material may be stored and remain suitable for use.
Orange colored resin which is the secretion of the Lac beetle found in greater quantities in India and Indochina. Shellac is ordinarily dissolved in denatured ethyl alcohol.
Usually associated with extensively crosslinked films, visible by the amount of curling induced on the substrate.
The degree to which tactile friction is absent from a film.
A measure of solvency whose major usefulness is in predicting whether a particular solvent will dissolve a particular resin. Based on heat of vaporization of the solvent. Stronger solvents generally have higher solubility parameter values.
A solvent which by itself will dissolve a resin.
A liquid, usually volatile, which is used in the manufacture of coatings, to dissolve or disperse the film-forming constituents and which evaporate during drying (does not become part of the dried film). Solvents are used to control the viscosity and application properties of the finished material.
A general term denoting the ability of a solvent to dissolve a resin or binder and hold it in solution. Also known as solvency.
Small specks of color lightly splattered onto a surface to add aesthetics.
The bands of color seen when white light, especially light from the sun, is broken up by refraction, as in a rainbow or prism.
The degree to which a coating can be finely atomized at the tip of a spray gun.
A pigmented material which can be sprayed or wiped onto wood to accent the grain patterns.
Telegraphing / Ghosting
The transmitting of surface irregularities in a previous coat through to a topcoat.
Resin which remains fluid on heating and hardens when cooled. Remains soluble in the original solvent blend and does not become insoluble upon heating.
Resin which polymerizes to a permanently solid and infusible state upon the application of heat. Once heated, will not dissolve in the original solvent blend.
A blend of solvents used to lower the viscosity of the coating prior to application.
The tendency of a coating to be low in viscosity under agitation but to “body-up” or become viscous when not agitated.
The ability of a film to absorb physical abuse without failure.
The difference between the amount of finishing material solids deposited onto the surface of the part compared to the total amount of finishing material solids sprayed.
The light rays which are outside of the visible spectrum at its violet end.
Any substance which contains active hydrogens capable of reacting with isocyanate will be restricted to very low levels. Specifications for urethane grade solvents typically center on very low water and alcohol contents, typically 0.1% water or less. Glycol ethers also contain active hydrogens and are not suitable for use in urethanes. Historically, esters have contained significant amounts of alcohol. More recently, alcohol free grades of esters have been produced with the designation “Urethane Grade”. The usual quality grades of hydrocarbons and ketones ordinarily are suitable for urethanes, even though they may not be designated specifically as urethane grade.
Materials based on isocyanate monomer reacted with other materials to yield polymers containing any ratio of urethane linkages, active isocyanate groups or polyisocyanate monomer. The resin may contain excess isocyanate groups available for further reaction at the time of application or may contain essentially no free isocyanate as supplied.
The crosslinking of a material upon exposure to ultraviolet radiation.
The resistance a cured film has against yellowing or chalking when exposed to ultraviolet radiation.
A liquid composition which is converted to a transparent solid film after application as a thin layer. Once the film has completely dried, it will no longer dissolve in the solvent blend from which it was applied.The resistance a cured film has against yellowing or chalking when exposed to ultraviolet radiation.
A crack that forms along the wood grain in a veneered substrate which subsequently cracks the coating surface.
Resins based on vinyl chloride monomer. Most frequently copolymerized with other monomers such as vinyl acetate. Most vinyl resins require very strong solvents, such as ketones, to form useful solutions.
The degree to which a coating resists flow or movement.
Instrument used to measure the rate of flow or movement of a material. Measured in elapsed time a material requires to pass through a given opening at a given temperature.
The weight of volatile organic material in 1-gallon of coating.
Any material which can evaporate under normal operating conditions.
A low-solids coating applied under a stain to limit penetration of the pigments into the wood.
A pigmented material which can be sprayed or wiped onto wood to color it and to accent grain patterns.