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.
Depth Of Printing. The quality of the negative has much to do with the required depth of printing, and this must be taken into consideration at all times, no matter what printing process is employed, or what tone is desired. For purple tones it is necessary to print a shade deeper than when warm tones are desired.
93. The necessity for deeper printing is explained by the fact that the toning is to be carried considerably further than for warm toning. All prints grow somewhat lighter in the toning, caused by the action of the toning agent; therefore, as you are going to tone deeper and longer, the print, unless printed darker, would become too light.
Preparing The Toning Bath. In securing warm tones the acetate of soda is used to restrain the action of the gold upon the highlights. As deep toning will require more restraining of the highlights a greater quantity of acetate of soda must be used. Care must be exercised, however, in adding the alkali, for too much causes muddy whites, and the nearer neutral the bath can be worked for deep tones the purer will be the whites. Acetate of soda is a more neutral chemical than borax, yet as a restrainer and purifier of whites, it is more advisable to employ-it than to resort to borax.
95. Should the bath become too alkaline by adding too much borax, the prints instead of remaining clear in the highlights will turn yellow and in the resultant print will be extremely muddy. Never add acetate of soda to the bath after beginning to tone, as it will have practically no effect, except when using the special acetate toning bath.
96. When toning collodion-coated paper proceed in exactly the same way as for gelatin, but use a trifle more alkali, or Solution No. 3. Never tone gelatin and collodion papers together in the same bath, nor wash these papers together in the same tray.
Flattening Collodion Prints. Collodion paper is apt to curl in washing; therefore, the following method of flattening should be employed: Pour sufficient fresh water into the washing tray to nicely cover the bottom, say one-fourth of an inch deep. Place the prints face side down, patting them with the palm of the hand to insure their thorough immersion. Place second print on top of first, partially over-lapping. Pat this print in like manner. Place all the prints in this way, spreading them over the bottom of the tray. When all prints are in the tray, allow them to remain for a minute; then pour off the water and set the tray on edge to drain for about two minutes. (See Illustration No. 4.) The reason collodion paper curls in the water is that the paper swells as soon as wet and the collodion emulsion does not. Therefore, if the print when first placed in the water is held flat, the paper swells in thickness only, and if the print is kept flat until the paper is thoroughly soaked in this position, it will remain flat during the entire manipulation. The tray can then be filled half full of water and the prints more freely handled, as they will not curl. Always keep them face side down, however, until washed. It is a good idea when using collodion paper to add a few drops of a saturated solution of common washing soda to the second washwater. This will neutralize the water and prevent red spots that may be caused by the perspiration on the fingers coming in contact with the surface of the papers while examining during printing.
Illustration No. 4 Flattening Collodion Prints. bee Paragraph No. 07
Illustration No. 5 Flattening Prints to Bottom of Tray.See Paragraph No. 168
AUTUMN Study No. 7 See Page 385 By Wm. Spanton.