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.
Using Silk Bolting-Cloth. When using Royal Bromide paper beautiful effects of softness and breadth can be obtained by enlarging through a silk bolting-cloth screen. This screen will break up the intensity of the blacks, and add to the breadth of the half-tones, and when prints so made are given a sepia tone they have the appearance of rare old etchings. "When enlarging from a portrait it does away almost entirely with retouching. The screen may be used in direct contact with the paper, in which case the enlargement has the effect of being made on fine meshed canvas. Greater diffusion of light, however, may be obtained by placing the screen at a distance of one-fourth to one inch from the paper. The further the screen is removed from the paper the greater the diffusion of light. When using the screen you must increase the length of exposure about one-third.
684. Use the fine mesh bolting-cloth for large prints on smooth paper; the medium or coarse mesh on rough paper; while for small prints use the fine mesh. You will find, by providing yourself with a fine mesh screen, and then producing the different effects by either printing in close contact or moving the screen some distance from the paper, you can produce the different effects almost as easily as if you had a number of screens of different mesh.
685. Silk bolting-cloth, especially adapted for enlarging, can be purchased from the Eastman Kodak Company, Rochester, N. Y. It is supplied in rolls, and is securely packed in pasteboard tubes to avoid creasing. It is put up in three grades-fine mesh, medium mesh and coarse mesh. It can be purchased by the yard or in 18 x 20 inch squares. A good plan is to tack this cloth securely on a stretcher so that it will be perfectly smooth, and before using it should always be carefully dusted with a soft brush.
687. Don't place the prints between blotters to dry.
688. Don't use the developing-dish for fixing.
690. Don't fail to keep the solution in motion while developing.
692. Don't expect to have permanent prints unless they are thoroughly fixed and washed.
693. Don't expect that the light reflected from a red brick wall will be sufficient for enlarging. Unless your enlarging window has an unbroken horizon you must use a reflector.
694. Don't use old developer on large prints for the sake of economy; use it fresh every time.