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.
Plain Prints. All negatives from which plain prints are to be made should be printed either in the shade, or under tissue or ground-glass, and not in direct sunlight, as printing in the sun produces a surface print, with no depth of brilliancy when finished. Weak negatives can be very much improved by printing in the shade under green tissue paper. If in the sun, put a white tissue paper over the green.
Fresh Paper. When paper prints brown or purple, with muddiness in the half-tones, it is quite fresh, and should be kept in a warm place (near a radiator) for a few days. Paper treated in this way will soon print a rich red color. Fresh paper must be printed darker than older paper, which prints a cherry red. When, during cold weather, paper gives prints with weak purple in the shadows, it is on account of chilling, the chemical action failing to take place freely. Always print in a warm temperature if you wish the best results. In the winter, paper thirty days old is much better than if very fresh. Older paper gives stronger, richer prints.
Holding Back Shadows. A simple method of holding back shadows on a face, or to lighten hair, drapery, etc., is to use a color (blue, or yellow) in solution. Apply with a small brush, in a net-work fashion, on the tissue over the parts to be lightened. This forms a filter screen.
Printing Dense Portions Of Negatives. Detail in highlights and dense portions of drapery can be brought out by using a hand magnifying glass. Focus the light through the glass on the highlights, or the parts to be printed up, and by moving the glass the detail can be printed out in a few minutes.
Thin Negatives. Stronger prints can be obtained from thin negatives by flowing the back of negative with a ground-glass varnish, colored green.
Printing In Highlights. Detail in white draperies and highlights can be printed in by applying, with a brush, a little common retouching fluid on the tissue (covering the frame) over the dense parts of the negative. Retouching fluid will not spread like oil, nor turn yellow as quickly as turpentine.
1123. "Home Made" Opaque. - No. 1. Add enough water to yellow dextrine to make it about the constituency of mucilage.
No. 2. Mix enough water with Indian Red (dry color) to make it about the thickness of paint.
1124. To make the opaque, add one ounce of No. 1 to four ounces of No. 2. This is good for spotting negatives or blocking-out vignettes.
1125. The solution " Dextrine " can also be used as a mucilage in sticking down tissues. It will not sour.