Color
In art, color is not essential to some forms and processes, as engraving, etching, charcoal work, and the various forms of crayon work; and in printing, it is absent from the large percentage of work done in black and white.
This limitation of the application of the word "color" in printing is quite arbitrary. If we speak in the strictest sense we must consider that black and white work is color work. White is the concentration of all the rays of the solar spectrum, the epitome of all colors; while black is the appearance of the substance that most nearly rejects all reflections of the spectrum colors; and black and white are as truly colors as are red, violet, vermilion, or any of the other brilliant tints. Yet as it is usual to allude to black and white as some other qualities than color, and as they affect us so differently, it is deemed to be more convenient to consider them in relation to light and shade, tone, and values, and to confine the meaning of "color" to the tints shown by the spectrum. This is not an insignificant distinction when employed in relation to printing, as much of the beauty and power of the plainly printed book page is due to the apportionment of black and white—black type and white paper. So when we speak of color in printing it must be understood that the word is not used in its broadest, nor in its most exact, sense; but in an arbitrarily restricted sense, applying exactly as it is applied by printers in actual practice.
The printer's understanding of color, his appreciation of its usefulness and power, is approaching toward the high esteem in which it is held by the painter. He is coming to know that it is a high quality of his work, and that by it he is able to suggest several other qualities that are vital, such as lights, shadows, perspectives, etc.
There are no explicit rules for the guidance of the printer in the use of color. There are certain fundamental principles, and many rules deduced from them, a thorough acquaintance with which will enable him to avoid serious blunders and greatly aid him in the working out of a scheme; but that sense of rightness which the successful artist or craftsman occasionally experiences, cannot be won by the mere following of the letter and the spirit of rules. How true this is becomes apparent when the work of the best printers is examined with intelligent care, and it seems absolute when the meager list of great painter colorists is reviewed: Titian, Giorgione, Tintoretto, Paul Veronese, Rubens, Velasquez, Delacroix, and a few with less claim to the title. All that is known about color has been absorbed by hundreds of artists; yet out of a great army of successful students there have come so few good colorists that their names can be spoken in ten seconds.
To effectively deal with color a fair understanding of what science is able to tell of its essential properties and powers is necessary as a basis. To this may be added such of the deductions and rules as have been formulated by the great painters and the students.
The important starting point is this: To realize that color is not a material existence, not a substance, not a fixed fact equally appreciable by all and equally demonstrable to all. It is a sensation; and a sensation not of the same force or quality for different individuals. Of itself it depends upon the waves of the ether in space; for us it depends upon the power and truth of our eyes. One may truthfully see a color that is quite another thing to another person, if there should chance to be a difference radical enough or defects serious enough in the eyes of either. The laws governing light are of great importance to the colorists. There are subtleties that have important practical application which cannot be guessed otherwise than by direct reference to science. In no other way can a printer know for example what colors are complementary or what effect a certain color will have upon another when they are used together.