Paint – A dispersion or suspension of pigment powders in a liquid vehicle.

Paint Failure – The loss of usefulness of the paint coating.

Paint Incompatibility - Loss of adhesion when a water-based topcoat is applied over many old coats of oil-based paint.

Paint System – The full number and types of coats covering a complete paint job.

Painting – All operations required to use paints properly.

Painting Materials – All materials. required to adequately paint a surface.

Pattern – Design that is repeated.

Peeling – Failure in which paint curls or otherwise strips from substrate.

Penetrating Finish - A coating that is absorbed into the substrate, rather than forming a film on its surface.

Permeable - Capable of allowing something (such as water vapor) to pass through without harm.

Petroleum Distillate - Liquid hydrocarbon solvents (such as mineral spirits) that are isolated or made from petroleum.

Phenolic Resins – Particular group of film formers; resins made from phenols and aldehydes.

Pickling – A dipping process for cleaning steel and other metals; the pickling agent is usually an acid.

Picture Framing - A non-uniform color effect that can appear when the corners are first cut in with a brush, and then the walls are rolled. The brushed areas generally appear darker, resembling the “frame” of a picture. Also, sprayed areas may be darker than adjacent sections that are brushed or rolled.

Pigment – A finely powdered, insoluble material used in paint to give color, opacity, and consistency.

Pigment Volume Concentration (PVC) - Percent by volume of pigment to total non-volatile volume.

Pilaster – Flat column superimposed on a plain surface as support for a cornice or pediment.

Plasterboard – see Drywall

Plastic Bonded Papers – Papers made with a protein size with plastic added. Washable but subject to staining by certain liquids.

Plastic Coated Papers – Papers and other wall coverings that are more washable and stain-resistant than plastic-bonded papers because of the thick plastic coating.

Polyester – Resins used in making plastics, fibers, etc.

Polymer – A large molecule formed by polymerization.

Polymerization – Chemical reaction in which small molecules combine to form large molecules.

Polyurethane Varnish - A clear coating that is based on a modified alkyd resin.

Polyvinyl Acetate (PVA) – A synthetic resin used extensively in emulsion (water) paints; produced by the polymerization of vinyl chloride.

Porosity – Degree of integrity or continuity.

Pot Life – The time period after mixing when liquid material is still usable without difficulty.

Pre-pasted Wall Coverings – Wall coverings to which the manufacturer has already applied paste. Dipping wall covering in water before hanging activates the paste.

Preservative - A substance used to prevent the growth of microorganisms in or on an organic base. An example is an ingredient in latex paint used to prevent spoilage.

Pre-trimmed Wall Coverings – Rolls of wall coverings from which selvage has been trimmed at the factory.

Pre treatment – Chemical alteration of the surface to make it suitable for painting.

Primary Color – Three colors in the spectrum each produced by a single wavelength. Red, yellow, and blue ate the colors.

Prime Coat – First coat on a substrate.

Primer – A paint coat used to prepare a surface before applying the finish coat.

Primer Sealer - A priming system that minimizes or prevents the penetration of the topcoat into the substrate.

Property – A quality; peculiarity.

Protective life – Interval of time during which a paint system protects substrate from deterioration.

Putty – Dough-like mixture of pigment and oil used to set glass.