to outside surfaces as well. Water-based paints fall into many categories, but casein, latex, and
calcimine are the more important ones.
(1) Casein. In casein paint, casein (protein of milk) is used as the binder. Casein paint
tinting colors. Small amounts of vegetable oils are added to improve its washability. The principal
pigment added to casein paint is titanium. Casein paints usually cover a surface wall in one coat, dry
rapidly, and adhere to new, unsealed plaster without blistering the paint. Use casein paints for interior
decorative work on plaster, wallboards, fiberboards, stucco, cement blocks, and such. Casein paints are
also available for exterior masonry, stucco, brick, and concrete.
(2) Latex (emulsions). This term was originally used to describe raw, latex rubber-emulsion
paint (rubber in water). Now, the term is used in connection with all resin and rubber-emulsion paints.
Water is used to both thin these paints and clean the brushes. Many types have been made, but vinyl and
acrylic emulsions are the most popular. Emulsion paints are very good for use on interior and exterior
masonry because they breathe, allowing vapor to slowly pass through the film. Emulsion paints are
glossless, and you must ground special colors in a suitable vehicle to color them.
(3) Calcimine. Calcimine is a mixture of powdered pigments, such as whiting and china
clay, and glue. You compound the paint by mixing the prepared pigments with water. The paint is an
inexpensive way to cover wet (damp) wall and drywall interior surfaces. A compound of glue, a tinted
wash, and calcimine may be used on wet walls. The best results, however, are obtained by using a
varnish sealer and primer before applying the calcimine.
e. Varnish (Resin). Varnish is a transparent or opaque liquid that provides protection and
decoration. It dries to a hard, transparent coating. The kinds and types of varnishes used are numerous.
Some manufactures' catalogues list from 100 to 200 varieties. Oil varnishes are the most frequently
used and include spar varnish, interior varnish, flat varnish, rubbing varnish, and colored varnish. All of
the above varnishes are extensively used to finish and refinish interior and exterior wood surfaces, such
as floors, furniture, woodwork, metal fixtures, and so on. They produce a durable, elastic, and tough
surface that dries to a high-gloss finish and does not mar easily. Exterior varnishes are specially
formulated to resist weathering.
f. Shellac. Shellac comes from the secretions of the scale insect. This insect secretes a
resinous material on trees which is gathered, washed, and ground, and then melted and formed into a
thin sheet. These thin sheets of shellac are then broken into flakes (one of the forms in which shellac is
sold on the market). Shellac is now produced with chemicals in modern factories. Shellac is soluble in
alcohol and used extensively on furniture as an undercoat and over knots to prevent bleeding.
g. Stain. Stain is used to change the color of various types of wood and to bring out the beauty
of the grain. They are usually applied before the varnish or other finish; however, some oil stains are
used as a preservative for shingles and other rough, exterior, wood surfaces. The most commonly used
stains are water, spirit, oil, and varnish.