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.
Small Brown And Black Spots. These are caused by air-bells gathering on the prints. They prevent the toning solution from coming in contact with the print and cause sulphurization, a gas being formed under the air-bell. Carefully remove all air-bells when the print is first placed in the toning bath. They will gather on the back as well as on the face of prints, and it is advisable to remove these also, as they are apt to cause air-bells on the surface of other prints.
Sticking Of Prints To Ferrotype Plates. If the ferrotype plate has not been thoroughly cleaned and you fail to use the solution given in the instructions, the prints are apt to stick. If ferrotype plates are used for a long time, they become old and lose their non-adhesive surface, and prints will stick to them. Carefully clean your ferrotype plate and apply the paraffin according to instructions, and you will have no trouble.
Dull Spots On Prints When Ferrotyped. When the print does not come in perfect contact with the ferrotype plate, airbells will gather between the print and the plate. Wherever there is an air-bell there will be little or no gloss. Squeegee your print in perfect contact with the plate and you will readily overcome this difficulty.
Pebble-Like Spots On Print When Ferrotyped. These little spots, which generally appear about the size of a pin-head, are usually caused by particles of dirt in the water. These particles prevent the print from coming in perfect contact with the ferrotype plate and, therefore, cause these pebble-like spots. As these spots will show through on the back of the print, raise it, remove the dirt, and then squeegee it again, bringing the print in perfect contact with the plate. If necessary, filter the water and you will avoid further trouble.
Perfect Contact Between Print And Ferrotype Plate.
When you place your ferrotype plate on the table or bench see that the latter is perfectly smooth, and that nothing is under the plate, so that when you place your print on it the squeegee will pass over perfectly even. It may take a little elbow grease to remove all air-bells, but keep at it until they are removed and you bring the print in perfect contact with the plate.
Ferrotyped Prints Lose Gloss Upon Mounting. This can only happen if you allow moisture to reach the surface of the print - damp blotters or damp fingers would cause it. Be careful that only dry blotters are used and that you dampen the previously pasted print, or the mount, just enough to make the prints stick.