The painter should stir his paint frequently, and strain it if necessary to get rid of any chunks and coarse material which are apt to settle to the bottom, and which, if left in the paint, may get into the brush, and be carried to the surface.
Paints for floors and the inside trim of houses often contain a small amount of varnish which makes a harder surface. For outside use a good spar-varnish may be mixed with the paint.
315. Hints and Precautions for Painters.—White-lead paints are poisonous if taken into the stomach. Dust from lead paints, if inhaled, may get into the throat, and finally into the stomach. There is very little danger, however, if the painter washes his hands before eating, and avoids the use of tobacco while painting. Tobacco which is handled with hands partly smeared with paint is dangerous. There is such a thing as lead-poisoning, but it is entirely preventable, and is a very rare disease.
Paints containing turpentine and benzine should not be placed near an open fire, as these solvents are very inflammable.
Ultramarine blue contains surplur, and should not be mixed with white lead or any other lead-pigment.
Turpentine is not recommended for use on the hands in removing paint. Linseed-oil will remove paint more easily, and then the hands can be washed with soap and water.
Benzine or kerosene are not good thinners, and should not be substituted for turpentine in paints.
Colored pigments should be added to the paste-pigment and oil while the paint is being mixed, rather than to the paint after it has been completely thinned.
Paints are more homogeneous if they, are mixed about 24 hours before using. According to some authorities, it is best to mix the drier into paint just before use. Paints that are not kept in sealed containers become fatty; they will not work smoothly under a brush, and are practically worthless after a short time.