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The Painters Dictionary
Paint Industry General Definitions
While there are many technical definitions used in the paint industry, here is a general glossary with those terms most widely used in order to give a working knowledge of basic product and painting terminology.
A to E
Accelerator: A catalyst material which speeds up the hardening of coatings. Acoustic Paint: Paint that absorbs or deadens sound.
Acrylic: A top quality resin used in water based paints which gives them the ability to expand and contract with changes of temperature. It also allows for washability, stain resistance and color retention.
Adhesion: Bonding strength, the attraction of a coating to the substrate to which it is being applied.
Airless Spraying: Using hydraulic pressure rather than forced air, to atomize paint.
Aliphatic Hydrocarbons: Flammable solvents of low solvent power, usually derived from petroleum.
Alkyd: A synthetic resin, used in the formulation and manufacture of the best oil based paints and enamels.
Alligatoring: The cracking of paint film which resembles the pattern on the hide of an alligator. Usually caused by paint drying in poor ventilation, recoating to soon, or "laying" a top coat before the first coat has had time to dry and cure.
Aromatic Hydrocarbons: Flammable solvents such as benzine, toluene and xylene.
Binder: A vehicle in which pigment is suspended such as resin; drying oil; latex emulsion or film former.
Bleaching: Loss of pigment color, usually due to exposure to sunlight.
Bleeding: To show through or beyond the bounds originally set. An example would be a stain that showed through the top coat. Bleeding can be avoided by sealing the stain with shellac or stain barrier. Then the top coat can be applied without the stain showing through.
Blistering: Pockets of swelling where the paint comes away from the surface, usually caused by air or moisture getting between the coating and the substrate.
Block Resistance: This term refers to the ability of a paint to avoid sticking to itself upon contact with another painted surface.
Bloom: A bluish-white haze that sometimes appears on a varnish film. Also used to denote a haze appearing on any coating film. It is generally caused by allowing the paint to dry in a poorly ventilated atmosphere.
Blushing: A term applied to lacquers becoming flat or in the case of clear lacquers, white or partially opaque . Usually occurs when lacquer is applied under very humid conditions
Body: The thickness or viscosity of a liquid. Usually referred to as the middle or undercoat.
Bonding: Adhesion. The joining of the coating with the surface.
Boxing Paint: Pouring two gallons of paint together to make sure both gallons will be the same color. Usually done by painters using the same color paint manufactured from different batches.
Breathe: The term used to indicate the sufficient porosity of a paint film, allowing it to expel or breathe out moisture vapors without suffering any detrimental effects such as blistering, cracking, peeling, etc.
Bridging: Forming a skin or film of paint over a depression in the surface.
Brushability: The ability of paint to be applied by using a brush.
Build: The relative thickness of a paint film.
Caking: A crust or compact mass formed from the setting of paint pigment.
Catalyst: A material that causes activity between two or more substances. Accelerator; curing agent; promoter.
Caulking Compound: A fluid-like putty used for sealing cracks around doors, windows and flashings.
Chalking: A powdery residue found on the exterior surface of paint, caused by the breakdown of the paint film ..
Checking: Slight breaks in the film that do not penetrate to the underlying surface.
Chlorinated Rubber: A film forming agent used as a binder. Made by chlorinating natural rubber.
Coal Tar Epoxy Paint: Paint in which the binder ,or vehicle, is a combination of coal tar with epoxy resin.
Color Retention: The ability of a coating to retain its original color.
Compatibility: A products ability to mix with or adhere to, other components or substances.
Composition: The resulting state, structure or make-up of a product.
Consistency: The thickness, body or resistance the paint offers to stirring or flow.
CoPolymer: A large molecule resulting from the simultaneous polymerization of different monomers.
Corrosion: Deterioration of a substance due to its interaction with the environment. Oxidation.
Coverage: The number of square feet that a gallon or quart of paint will cover.
Cracking: A condition caused by the aging of the paint film. Cracks or separations appear in the paint surface.
Cratering: The formation of holes or deep depressions in the paint film.
Crawling: The shrinking of paint shortly after applications which forms uneven surfaces.
Crazing: The development of tiny scales or cracks creating a non-uniform surface appearance.
Crocking: The removal of color pigment from paint film by harsh abrasion or rubbing.
Curtains: Sags in the paint surface that have the appearance of drapes.
Cutting-In: The application of paint in a straight line around doors, window panes etc. without flowing the paint onto non-paintable surfaces.
Dispersion: The suspension of one substance into another.
Drag: The resistance paint offers to brushing.
Drier: The chemical which promotes oxidation or drying of paint.
Drop Cloth: A large tarp or piece of fabric used to protect furniture, rugs and other objects from paint spills and splatters.
Dry Film Thickness: The depth of an applied coating when dry, expressed in mils (1/1000 inch).
Drying Oil: An oil which hardens when exposed to air.
Drying Time: The time interval between application of the paint and a specified condition of dryness.
Dry Rot: This term refers to types of decay, usually in wood. Identified by the affected wood being easily crushed to a dry powder.
Dry to Handle: The interval between paint application and the time it can be or picked up without damage. (usually relates to the painting of an object)
Dry to Recoat: Interval between application and ability to receive the next coat satisfactorily.
Dry to Touch: Time interval between application and ability to be touched lightly without damage (tack-free time).
Efflorescence: The deposit of soluble white salts on surfaces of brick or masonry.
Eggshell: A degree of shine between semi-gloss and flat.
Elasticity: The property of a film which allows it to stretch or change size and then return to its original condition without breaking or rupturing.
Elastometric: A coating system that features waterproofing and elongation, which allows expansion and contraction with the substrate.
Emulsion: The suspension of very small particles of oil in water or water in oil.
Emulsion Paint: Water-thinned paint with an emulsified oil and/or resin or latex vehicle .
Enamel: Paint which is characterized by it's ability to form an especially smooth film.
Epoxy Resins: Film polymers usually made from bisphenol A and Epichlorohydrin.
Erosion: The wearing away of paint film, leaving the substrate or undercoat exposed.
Ester: Compounds formed by the reaction of alcohols with organic acids.
Etch: Preparing metal or concrete surfaces using chemicals.
Extender: Pigment that contributes specific properties to paint.
F to O
Fading: A weathering condition caused by ultraviolet light. The breakdown of paint film and color, causing "bleaching".
Feather Edge: Tapering the edge of a film of dried material either by sanding or rubbing so it blends with the surrounding surface and results in the smooth application of the top coat.
Ferrous: Containing Iron.
Field Painting: Painting at a job site.
Filler: A substance to thicken or add texture such as an Extender, bulking agent or inert pigment.
Film: A layer or coat of material applied to a surface.
Film Build: Thickness characteristics of a dry coating.
Fire-Retardant Paint: Paint which will delay flaming or overheating of substrate.
Fish Eye: See Cratering.
Flash Point: The lowest temperature at which a flammable material will bum if a flame or spark is present.
Flashing: A condition where the top coat will dry both shiny and dull with paint from the same can. Caused by not priming and sealing the surface prior to painting.
Flat: Having no gloss or luster.
Flat Wall Paint: Paint that has no sheen when it dries. Excellent for hiding imperfections in the wall finish.
Flatting: The loss of gloss in a coating film.
Floating: Separation of pigment colors which then float on the surface of the coating.
Flocculation: Pigment particles that cluster together. Flocculation causes loss or unevenness of color and sometimes can be broken down by brushing.
Flow: A measure of how paint is self-leveling.
Frosting: A salt like deposit that may appear on the surface of an exterior paint. Most noticeable when darker colors are applied over white paint made with calcium carbonate.
Fugitive: Generally refers to pigments that fade in sunlight or under heat.
Fungicide: A substance that retards or prevents the growth of fungus.
Galvanized Steel: Steel that is plated in a bath of molten zinc.
Ghosting: When a surface coated with a flat paint appears to be flatter in some areas rather than others.
Gloss: Shininess; the ability to reflect light.
Hardener: A curing agent or catalyst that promotes, drying or hardening.
Hiding: The ability of paint to hide the surface which it covers.
High Build: Thick dry film produced by the paint.
Hold Out: Property of a surface material that prevents paint from soaking into the substrate.
Holiday: A pinhole, skip, discontinuity or void in the paint surface.
Hue: A specific quality that distinguishes one color from another.
Hydrolysis: The term is used to describe the reaction that can occur when some paints (particularly alkyds) are applied to fresh masonry that is still very alakline, resulting in color change and film deterioration.
Incompatible: Paints that will not mix homogeneously without impairing their original properties.
Inert Pigment : A non-reactive pigment.
Inhibitive Pigment: A pigment capable of retarding the corrosion of metal over which the coating is applied.
Intumescence: The ability of fire retardant paint to form an insulating barrier between the paint film and the surface of the material.
Kalsomines: Water paint coatings made with whiting, glues, etc.
Ketones: Flammable organic solvents . Commonly used examples are: acetone, Methyl Ethyl Ketone (MEK) and Methyl Ethyl Isobutyl Ketone (MIBK).
Krebs-Stormer Viscometer: An instrument for measuring the consistency of paint using Kreb Units or KU's .
Lacquers: A hard, glossy, varnish coating which dries by the evaporation of the solvent.
Laitance: The milky white deposit on new concrete.
Lap: To lay or place one coat of paint so its edge extends over and covers the edge of the previous coat.
Latex: A common, natural or synthetic, rubber-like binder for emulsion (water) paint.
Leafing: The orientation of pigment flakes in horizontal planes.
Leveling: Paint flowing with uniform thickness. The tendency of brush marks to disappear.
Lifting: The top coat of paint not adhering to a previous coat usually resulting from not allowing the first coat to dry sufficiently before reapplication.
Light Fastness: The ability of a color or film to withstand the effects of exposure to light and not change color.
Livering: The formation of curds or gelling of paint.
Long Oil Varnish: A varnish with a high ratio of oil to resin mix. (25 gallons or more of oil per 100 pounds of resin)
Masking: Covering of surface areas that are not to be painted.
Mastic: A heavy bodied, high build coating.
Matte Finish: Having a flat, smooth, even surface free from shine or highlights.
Metamerism: A term referring to how the appearance of one color can change in the relationship to another color when viewed in different lighting conditions. For example; a match acceptable from sample to sample indoor fluorescent light may not be so under incandescent light.
Mil: One one-thousandth of an inch: 0.001", 1/1,000 inch.
Mildew: A fungus which can feed on paint film. It looks like black dirt and must be killed, scrubbed and washed before the surface can be repainted.
Mill Glaze: A smooth, hard layer of natural woods resin which forms on the surface of Cedar and Redwood during the manufacture of smooth siding trim.
Mineral Spirits: Aliphatic hydrocarbon solvents.
Mud Cracking: An appearance that occurs in coatings that looks like mud drying in hot weather.
Non- Volatile: The solid, non-evaporating portion of the paint left after the solvent evaporates.
Oleoresinous: A film former containing oil and resin.
Opacity: The hiding power of paint.
Orange Peel: The dimpled texture of a dry film that resembles an orange peel.
Oxidized Film: A coating which has lost its gloss and/or become powdery.
P to W
Paint: A mixture of pigment and solvent which forms a solid adherent covering when applied to a surface.
Pearl: A term generally referring to paint with a gloss between eggshell and semi gloss.
Peeling: The breaking away of large portions of old paint. Usually caused by moisture or poorly prepared surface.
Phenolic Resins: Refers to a particular group of film formers. Resins made from phenols and aldehydes.
pH Value: The measure of acidity or alkalinity. pH7 is neutral; the pH value of acids is less than 7 and of alkalis (bases) greater than 7.
Pigment: An insoluble material that provides an obscuring value, color or protection to paint.
Pigment Volume Concentration (PVC): Percentage by volume of pigment in a dry film.
Pin- Holing: The formation of small holes through the entire thickness of a coating. Also see cratering.
Plasticizer: A paint ingredient that allows elasticity and flexibility.
Polyamide: An amine containing polymer; used for catalyzing epoxy resins.
Polyester: A thermosetting resin formed by polymerization. Used widely in making fibers, plastics and coatings .
Polymerization: A chemical reaction in which small molecules combine to form larger molecules.
Polyurethane: (see urethane).
Porosity: The ability to be permeated by liquid or air. The degree of a coatings continuity and integrity.
Pot-Life: The time which a liquid material is usable after the mixing of reactive components.
Prime Coat: The first coat on a substrate .
Primer: Material used for the prime coat; usually a rust-inhibitive for metal or sealer for untreated wood surfaces .
Red Label: Flammable of explosive materials with flash points below 80°F, (26.7°C).
Reduce: To decrease the consistency of a product by the addition of a thinner such as mineral spirits or linseed oil.
Reflectance: The degree of light reflection .
Resin: A natural or synthetic material contained in varnishes, lacquers and paints which forms the coatings film.
Ropiness: A stickiness in some paints that results in an irregular pile up of film, giving the appearance of rope. In the Western States only, this same term applies to a film having poor flow or showing brush marks.
Runs: Irregularities in the application of paint caused by too much paint on the brush or not brushing out the paint adequately .
Rust: The formation of iron oxide. A result of the corrosion of iron or steel.
Sagging: A term to describe the running of paint when too much is applied to a hot surface. May be caused by adding too much paint thinner to the paint before application.
Saponification: The process of oil or fat turning to soap when in contact with an alkali .
Satin Finish: Refers to decorative paints, usually between a semi-gloss and a flat.
Scaling: An indication of paint failure where moisture enters the cracks in the paint film destroys its adhesive property and results in the breaking or scaling of paint. Also a term to describe the cobwebb appearance of varnish when the top coat has been rubbed through.
Scrubbability : The ability for paint to stand repeated scrubbing once the film has dried and seasoned .
Sealer: A thin liquid usually applied to wood, plaster, gypsum board or masonry to prepare the surface for painting.
Seeding: Aggregates of pigment or vehicle particles that show up as a "sandy" effect when the material is applied. Usually a result of a chemical reaction.
Shade: Gradations of color.
Shelf Life: The length of time a material may be stored and still be useable.
Shellac: A clear, paint-able liquid used as a sealer to prevent stains from bleeding into a new top coat.
Shop Coat: A coating applied to material in a fabricating shop before it is shipped for use.
Short Oil Varnish: A brittle varnish prepared by cooking a relatively small quantity of oil with resin. (less than 25 gallons of oil per 10 pounds of resin)
Silicone Resins: A group of film formers used in water-repellent and high temperature paints. Organo-Silicone Polymers.
Silking: A surface defect characterized by parallel hair-like striation in the coated film.
Skin: The film found on top of paint left in storage. Formed by air seeping through the container seal. Remove any skin before using.
Skips: Uncoated areas. Also see Holidays.
Solids: The non-volatile portion of paint.
Spackling Compound: A paint-able compound used for filling cracks and holes in the substrate.
Spalling: The cracking, breaking or splintering of materials, usually due to heat or freezing.
Spar Varnish: A varnish made for exterior surfaces.
Specular Gloss: A gloss that produces a mirror-like finish.
Spreading Rate: The area covered by a unit volume of coating. Frequently expressed as feet per gallon.
Stain Blocking: The capability of certain primers to prevent the substrate from staining the top coat.
Streaking: Lines of various shades of paint which appear during and after application. Caused by the paint not being stirred, applying it in hot weather or uneven drying.
Styrene-Butadiene Resin : A co-polymere of styrene and butadiene .
Substrate: The surface to be painted.
Suction: The absorption of oil or other vehicle in a finish coat. Areas of uneven texture.
Surfacer: A paint used to smooth the surface before finish coats are applied.
Tack: The degree of stickiness of drying coatings.
Tack Rag: A piece of loosely woven cotton clothe that is dipped in varnish and wrung out. It soon becomes tacky or sticky and can be used to wipe a surface to remove small particles of dust.
Thinners: Volatile organic liquids used in reducing viscosity. Solvents.
Thixotropic: A gel which liquifies when stirred or shaken and then returns to a gel when left standing.
Tint: A color produced by mixing white paint and pigment with a non-white colored paint or pigment.
Tint Retention: The ability of an exterior paint to maintain its color over years of exposure.
Tipping: Using the tip of a paint brush to even out already applied paint.
Tooth: The roughing up of a surface to promote better adhesion between two coats of paint.
Total Volume Solids: The total solid film contained in paint, expressed as percent
by volume, or mil-square feet per gallon . One gallon volume is equal to 1600 mil square feet.
Urethane Resins: A specific group of film formers, i.e. isocyanate resins .
U.V. Absorber: Special materials added in small quantities to paint in order to absorb ultraviolet light and increase the life span of the paint.
VM&P Naptha: Varnish & Paint Manufacturers naptha. A low power flammable hydrocarbon solvent.
Vehicle: The liquid carrier and binder of pigment, or any other additive in paint. Vinyl Resins: Synthetic resins made from vinyl compounds such as vinyl acetate. Viscosity: The degree of a paints liquid density.
VOC (Volatile Organic Compounds): Any carbon compound that is released into the atmosphere during the application, drying and/or curing of coatings.
VOS: Volatile Organic Substance. Essentially the same as VOC.
Volatile Content: Ingredient materials which evaporate. Usually expressed as a percentage of the compound.
Washability: The physical ability of a paint to be washed without it losing surface integrity.
Wet Adhesion: The ability of a paint to maintain adhesion to the substrate when subjected to wet or damp conditions.
Wet Crocking: The tendency of paint color to transfer to a wet rag when the surface is rubbed. Dry Crocking - is when the same thing occurs with a dry rag.
Wet Edge: The ability of a paint to be repainted in wet condition without showing lap marks.
Wet Film Thickness: The thickness of a film immediately after application.
Wrinkling: The creasing of the top coat of paint when applied too thickly over a previous coat that is not completely dry.