This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
416. The gum-bichromate process excels all known photographic printing processes in cheapness, simplicity and artistic interest. Its greatest achievements are to be found in the work of the advanced amateurs of all countries, yet it is a process which will give infinite pleasure and instruction to even the beginner. It has frequently been stated that no one without the skill of an artist should attempt this process, and, in truth, this is so where any attempt at "manipulating" the print is made. But as a reproductive process, capable of rendering a picture in broad tones, yet with sufficient detail, and in any desirable color, it is worthy of being known and worked by every photographer.
417. It is, further, a process which is much made use of by more pictorially inclined professional photographers, and it has this essential charm about it, that when any hand work is done on the print itself it is almost impossible to achieve exactly the same result in any two prints from the same negative. There is thus a forced individuality about such prints which no other process can equal.
418. What the Gum-Bichromate Process Is. The Gum-Bichromate Process is a contact method of printing in any color, on any paper, from any class of negative, by means of the action of light on a pigment contained in a gum or other colloid coating on paper which has been made sensitive by a solution of bichromate of potassium or bichromate of ammonium or both.
419. Its Limitations. That there are certain crudities in such a process can readily be understood. For instance, while it is entirely possible to obtain a bichromate image showing almost the complete detail of a fine negative, yet it is most difficult to obtain such a print, and besides, it is not the province of the"gum-bichromate print to compete with a gelatin surfaced picture in lineness.
420. Again, the surface of the image when the print is in the developing water is of such a nature that the least careless handling will mar the print, or remove color from some spot where it is not desired that color should be removed.
421. Again, if the worker attempts to manipulate the print in the developing water, and is not skilful in the use of his simple tools, or has not any clear idea of what he wishes to produce or alter, or is without some little training in drawing, the results will be generally inartistic, if not actually false to nature.
422. Results Obtainable. Given, however, a certain knowledge of drawing, and with a clear idea of the result required, the gum-bichromate process in the hands of a skilful worker will give prints that are not to be equalled for breadth, atmospheric effect, pictorial and artistic quality. The foremost workers of the world have for years made the gum-bichromate process particularly their own, and while many classify it as a splodgy, mussy, non-photographic process, it cannot be denied that it lends the photographer those elements of individuality which are not nearly so prominent in other printing processes.