The practical printer : a complete manual of photographic printing (1874)
Hearn, Charles W · Philadelphia : Benerman & Wilson · leaf 180
168 THE PRACTICAL PRINTER. Cleaning Old Plates. — For the purpose of cleaning old dirty plates which have been used before, whether varnished or not, they should first be placed in a bath made of concentrated lye 1 pound, water 1 gallon. Let them remain in this hath until the film will be easily… … When this time has arrived, then wash well under the tap until all of the varnish and film is removed, and then place them one by one in the acid bath as described above. Keep the old plates in the lye until all of the film is removed, and never place them in the acid until that time arrives. In…
Photography -- Printing processes · Photographs on porcelain
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
