Painters Boston MA
A Painting Glossary
Acrylic: A type of synthetic polymer used as the binder for high-performance, water-based paints and caulks.
Alkyd: A synthetic resin used in oil-based paints.
Alligatoring: A scaly pattern that appears on paint due to the inability of the paint to bond to a glossy coating beneath it. It can also be due to the application of a hard coating over a soft primer, or (with oil-based paint) because the wood was re-coated before the undercoat was dry.
Binder: A component of paint that binds the pigment particles into a uniform, continuous paint film and makes the paint adhere to the surface. The nature and amount of binder helps determine most of the paint's performance properties.
Chalking: Deterioration of the surface of an exterior paint, upon weathering, into a faded, powdery substance. Chalking occurs when the paint's binder is degraded by harsh environmental conditions.
Checking: Patterns of short, narrow breaks in the top layer of paint. Checking occurs when the paint loses its elasticity.
Chime: The lip around the opening of a paint can into which the lid is placed.
Enamel: Technically, enamel is a colored varnish or high-gloss paint. Generally, the term is used for high-quality, dirt-resistant paints (generally for interior use) that may have a sheen from satin to glossy. These coatings are used for more demanding applications like in kitchens, bathrooms, etc.
Lap: Area where a coat of paint or other coating extends over an adjacent fresh coat. The painter's objective is to make this juncture without visible marks.
Latex paint: Water-based paint made with a synthetic binder, such as acrylic, vinyl acrylic or styrene acrylic latex.
Lead: A soft, malleable heavy metal. In the past, compounds of lead were used as a white pigment in primers to prevent tannin bleed-through.
Mud-cracking: A paint failure that looks like cracked mud. It occurs when a coating is applied too thickly, such as heavy application in corners.
Non-volatile: The solid portion of a coating consisting of pigment and binder; it is the portion of the coating left on the surface after it's dry.
Oil-based paint: Paints made with a drying oil, such as linseed, soya or tung oil, as the vehicle and binder, and mineral spirits or paint thinner as the thinning agent. They generally dry very hard but take longer to dry than latex paints and require more time to re-coat.
Polymer: A plastic-like material produced from chemical monomers that have been produced from alcohols and petrochemicals. Certain polymers are used as latex paint and caulk binders. The binder's polymer particles are small and carried in water. The binder polymer particles and water mixture is known as an emulsion or as latex.
Polyurethane varnish: A clear coating based on a modified alkyd resin.
PVC: Pigment volume concentration (also called pigment volume content). The ratio of the volume of pigment to the volume of total non-volatile material (i.e. pigment and binder) present in a paint. The figure is usually expressed as a percentage. Higher percentage figures are associated with flat paints; lower figures with gloss and semigloss paints.
Sag: Narrow (or wide, curtain-like) downward movement of a paint or varnish film; may be caused by the application of too much coating, the collection of excess quantities of paint at irregularities in the surface (cracks, holes, etc.), or excessive material continuing to flow after the surrounding surface has set. Also referred to as runs or tears.
Saponification: A chemical decomposition of a paint's binder by alkali and moisture from a substrate (e.g., new concrete or fresh plaster). Saponified paint may deteriorate, lose its adhesion and become discolored.
Solids: Non-volatile matter in the composition of a coating or a caulk, i.e., the ingredients in a coating that, after drying, constitute the dry film. Solids are composed mostly of pigment and binder.
Surfactant leaching: Also called water-spotting and weeping. It is often a tan-colored, glossy residue that can form on the surface when exterior latex paint is applied under conditions that are cool and damp, which results in slow drying of the paint. May not readily wash off, but will generally weather off within a month's time.
Tooth: In a dry paint film, a fine texture imparted either by a proportion of relatively coarse or abrasive pigment, or by the abrasives used in sanding; this texture improves burnish properties and provides a good base for the adhesion of a subsequent coat of paint.
Urethane: A type of binder used in coatings, characterized by excellent flexibility and chemical resistance. The terms urethane and polyurethane apply to certain types of binders used for paints and clear coatings.
VOC: Volatile organic compound. Any carbon compound that evaporates under standard test conditions. Essentially, all paint and caulk solvents except water are classified as VOCs. Some government agencies are limiting the amount of VOCs permitted in paint because of concerns about environmental and health effects.
Volume solids: The volume of the solid components (pigment plus binder) of a paint or caulk, divided by its total volume, expressed as a percentage. High volume solids provide a thicker, dry film, resulting in improved hiding and high durability.
Wet adhesion: The ability of dry paint or caulk to adhere to the surface in spite of wet conditions. This is of particular importance for exterior paints and caulks.
Wet edge retention: The length of time a newly applied coating can stand then be brushed or rolled again without showing lap marks.