Although to accurately test the quality of a color requires somewhat elaborate experiments, both chemical and practical, yet there is no reason why the painter should not determine with a sufficient degree of accuracy for his purpose the quality of the color he uses. Indeed, if this was done more generally, much of the adulterated trash would be driven from the market, and none would rejoice more at such a result than the color manufacturers themselves. The manufacturers assert that they are as desirous that the trade should use pure colors as the painters can possibly be. Even the biggest houses produce cheap grades of colors, and this they do, as a rule, almost under a protest and simply because they are compelled by painters demanding colors for certain low prices, far below that at which it would be possible to produce the pure article. Make careful comparison between pure colors and those being used. At the same time, compare the prices and see which is cheaper to use. If even they come out at the same price, remember that by using a pure color all the benefit of the purity of tone so necessary for the execution of good work is gained.

The first thing to be done. in testing any paint material is to have a standard. There must be no doubt about this. Unless we have in each case something with which to compare the particular sample of color that is being examined, we shall have no useful information concerning it. Take, therefore, good decorators' colors of well known make. If necessary purchase small tubes of the best colors, such as are put up for artists' use. This will be rather a severe trial, but still it will afford a standard. Having such samples and going through the tests we are about to describe, the painter can, after some amount of trouble, arrive at results which are almost as accurate as those which could be deduced by a chemist. An expert on this question some years ago summarized the characteristics of colors which should be considered in making the examination, under the following heads:

1. Purity of the material.

2. Purity of the tone, brilliancy; richness, which indicates the amount of care in selection.

3. Fineness of grinding or preparation; this means the degree of the division of the particles and upon the completeness of such division will depend

4. Its spreading capacity.

5. Its body. This applies, of course, only to opaque or semi-opaque colors. Body is opacity, and means capacity to conceal the surface to which the paint is applied, and must not be confused with spreading. It is an inherent quality.

6. Its staining power or tinting strength with white or colors.

7. The quality of purity of the tint with white.

8. If a paste color, the consistency of the paste.

9. Transparency of transparent colors and the quality of the transparency.

10. The permanency of the colors.

It will be observed that all of these tests will not necessarily be applied to every color. For instance, a transparent color would be tested for its transparency, but certainly not for its body. The one condition is the converse of the other.