The quality in a painting which is known as "values" may quite easily be regarded by the printer as signifying to him the same as tone. Careful study will show him that there is a difference, and also that value is a vital element in his work which has for him a real significance. Value may not unfairly be considered to be an element of tone. It relates to the intensity of light; not the brilliancy of color, but the capacity that resides in color to reflect light. In color printing the value of the most common colors ranks with yellow first, then orange, green, red, blue, and violet. That is, yellow is capable of reflecting more light from the same quantity of sunlight than any other color, and violet less than any other color. Scientists have reckoned that chrome yellow reflects 80 per cent of light, green 40 per cent, etc. These figures serve no very practical purpose, because the reflecting power of any tint is dependent upon the other colors employed. Colors are dependent upon each other for their value as well as for their intensity and their harmony. It is not difficult to treat this matter of value in a mathematical way, as is suggested by Prof. J. C. Van Dyke: "Let the chrome yellow with its 80 per cent of light represent a sunset sky in the background; let the green with its 40 per cent represent the grass in the immediate foreground; and let the orange-red with its 60 per cent represent the sail of a Venetian fishing vessel upon the water of the middle distance. Now we have the three leading pitches of light in the three planes of the picture," and the problem would stand thus: 40:60::60:80 and the result will indicate the relative power of the value in the picture.
Interesting, but not especially useful, the "practical" printer says. No, not unless there is recognizable in this, as in all that has been said about art in printing, the subtle relation between the vital elements of graphic art and those refinements of knowledge and practice which tend to bring printing nearer to the arts. The connection is there, and is evident to the seeing eye. In nature and in life the sense of values is of such importance that without it objects would not have relative positions; all would be a jumble of shades and tones, objects and colors; we would stumble, as we could not see depressions; we would grasp an arm or the empty air, when we attempted to seize a hand; we could not judge distances. It is upon the extent and the thoroughness of the printer's knowledge of this question of values that the degree of refinement and truth he is able to impart to a certain class of work depends, and hence its money value to him and its intrinsic value to his patrons.
Paper
Paper is as important an artistic or esthetic element in the well-made book as it is as a technical element; and it is likewise to be regarded from the point of view of the optician and the physiologist.
It is possible to select a paper for any book that will lend itself to the artistic scheme of the book. It has not long been possible to do this. The product of the skilled paper maker has more than quadrupled, in artistic variety, during the few years last past, until it is now the fault of its designer if a book intended to be harmoniously artistic is not as true to its motive in paper as in typography or binding. But it is evident that paper for a book cannot be selected without reference to the typography, the plates, and other mechanical features. A grade of paper that would be appropriate for the printing of a rugged-faced type (like Caslon) upon, would not do at all for a conventional type, such as the Scotch face, it might be discovered, even though the paper, in texture and finish, seemed to be peculiarly appropriate for the literary motive. There are certain type faces which may be printed upon paper that is milk white, and certain other faces that lend themselves more readily to the production of harmonious tonal effects when the paper has a "natural" tint, or is thrown strongly toward a brown color. Either of these combinations, or any similar combination, may harmonize unfavorably with the literary motive, or with the scheme for proportion and balance, or with the tone and values element, and though admirable in itself have to be finally rejected.
The weight and texture of the paper have to be considered as minutely and as carefully, and with the same principles in full view. A delicate and shy literary motive must not be given the massive dignity of heavy handmade paper and large and strong type. Such a scheme is harrowing to a sensitive reader's nerves and rudely subversive of the more obvious and elemental artistic principles.
It is a complex and an involved process to select the proper paper for a given piece of printing, and the rightful decision of either of the component elements involves the rightful decision with reference to each of the others. It is impossible to consider the question of paper apart from a consideration of the typography, the illustrations, the format, and the binding; and it is not possible to consider either of these elements apart from the literary motive, which must always be the foundation of the structure.