Mineral Spirits
Paint thinner. Solvent distilled from petroleum.

Naphtha
A petroleum distillate used for cleanup and to thin solvent-based coatings.

Natural Resins
Resins from trees, plants, fish, and insects.

Nonvolatile
The portion of a coating left after the solvent evaporates; sometimes called the solids content.

Oil Paint
A paint that contains drying oil, oil varnish or oil-modified resin as the film-forming ingredient.

Oleoresin
A natural plant product that contains oil and resins. Turpentine is an example.

Oxidation
Chemical reaction upon exposure to oxygen. Some coatings cure by oxidation, when oxygen enters the liquid coating and cross-links the resin molecules.

Paint
A coating including resin, a solvent, additives, pigments and, in some products, a diluent. Paints are generally opaque, and commonly represent the portion of the industry known as "architectural coatings.”

Paint Remover
A chemical that softens old paint or varnish and permits it to be easily scraped off. Also called "stripper.”

Paint Thinner
See Mineral Spirits.

Penetrating Finish
A finish that sinks into the substrate, as opposed to settling on the surface.

Pigment
Insoluble, finely ground materials that give paint its properties of color.

Polyvinyl Chloride
A synthetic resin used in the binders of coatings. Tends to discolor under exposure to ultraviolet radiation. Commonly called "vinyl.”

Primer
First complete coat of paint of a painting system applied to a surface. Such paints are designed to provide adequate adhesion to new surfaces or are formulated to meet the special requirements of the surfaces.

Resin
Synthetic or natural material used as the binder in coatings. Can be translucent or transparent, solid or semi-solid.

Rosin
Natural resin obtained from living pine trees or from dead tree stumps and knots.

Semi-gloss Finish
Finish that has a low luster sheen. Semi-gloss paints are formulated to give this result (usually 35-70 degrees on a 60-degress meter).

Shellac
A coating made from purified lac dissolved in alcohol, often bleached white.