This may be illustrated by a selection as follows: First lay in order the normal spectrum colors with the pure colors found in the first section of the sample book, thereby forming the central vertical column of Fig. 10. Then substitute for the orange, green and violet, those colors selected from the collection of broken colors, and the result will seem to render the operation absurd, but it is the same in principle as the results produced in the attempt to form a spectrum by the combination of three primary pigments, red, yellow and blue, because so produced the orange, green and violet, show by disk analysis from 54 to 80 per cent of black and white and are therefore as much broken as the corresponding colors in the papers of the broken scales, but not exactly the same in tone.
Engine Colored Papers.
Those papers which are termed "Engine Colored Papers" are so named from the process of manufacture as distinguished from "coated papers" which comprise the first three sections of the book. In coated papers a white paper is covered with a coating of colored pigment "fixed" with a small amount of white gum, gelatine or glue, and in this way the pure color of the pigment is obtained. In the engine colored papers the color is mixed with the paper pulp in the process of making the paper. In a paper mill the tub or vat in which the pulp is kept stirred up and perfectly mixed is called the engine, and hence this technical term has been applied to such papers as are colored in the pulp. In this class of papers both sides are alike, and for this reason in some of the folding exercises these papers are preferred, also because they are thinner and tougher. Heretofore, it has been impossible to obtain engine colored papers in "families" or scales, but in this assortment the numbers from one to six, furnish six scales of three tones each, comprising the normal tones with tints and shades. Following these from seven to sixteen are a collection of unclassified colors including grays which are much used. All these can be analyzed and classified by the color wheel. Black and white complete this class. It is impossible to make any close approximation to a black in this class of papers, as when they are compared with the coated blacks the result is a very gray black, or very dark gray. All the colors in these papers from No. 1 A to No. 13 are quite light broken spectrum colors, but less broken than the coated papers designated as broken spectrum colors.
While great care has been bestowed on the original selection of the colors of all these above-described papers and every effort is constantly exercised to keep them the same from year to year, the subject is materially complicated by the guarantee required of the manufacturers that no arsenic colors shall be used in the preparation of any of the papers. This guarantee is strictly insisted on, because, while the writer has never been able to learn of any authentic case where a child has been injured by the use of plated or glazed papers, he believes that the opinions of parents and teachers should be respected in the matter, although the arsenic colors are often the most permanent and the aniline substitutes which are necessarily used belong to a class which is the most fugitive of all colors.
The line of colored papers now in use is the result of many experiments on the part of the writer and careful tests by experienced teachers for several years, and in its present condition affords but small indication of the time and care which has been expended on it. This has been inevitable, because the peculiar system on which the colors are based has been one of growth and the papers have been designed to afford the necessary material colors for this special scheme of instruction.
In preparing the tints and shades in the papers many experiments have been made to determine the true effect of light and shadow on each normal color, and then to imitate these effects in the papers.
All this is independent of the professional tricks which artists use to heighten their effects, some of which are legitimate, while others may be questionable on sound principles.
It is a common habit with artists to introduce very warm effects into all sunlight by the use of orange or yellow in the warm colors. This extreme tendency has been intentionally avoided in the preparation of these papers, however desirable or allowable it may be considered in heightening effects. So also in the shades as in the tints, the aim has been to keep all the tones of one color in the same scale, even though artists often run the various tones of the same piece of color into two or three analogous scales.
It is the object of color education to train the eye to see color wherever or however it may be produced, either by actual color reflection or contrasted effects, and in order that these effects may be understood as explained under Simultaneous Contrasts it is necessary that the prepared material be truthful to nature, the more so because these effects are sometimes greatly exaggerated by artists.