Finger marks are often very-useful in detecting criminals, but they have no advantages that we know of in the various photographic processes. Sometimes they lead to a solution of a certain difficulty, but as a rule, it is a hard matter to get anyone to claim the finger print.

We have recently seen some beautiful examples of a difficulty which is very trying but is easily avoided. Many photographers have a habit of taking exposed plates out of a holder and transferring them to a plate box until they are ready to develop. There is nothing wrong with the idea, but the way the plates are placed in the box makes a great difference. The first plate should always be placed in the box, glass side down. This prevents the emulsion side from coming in contact with any chemical dust or moisture that may have been taken up by the pulpy board of which the box is made.

Place the first plate in the box, glass side down, and the second plate glass side up, with nothing between the two.

This brings the emulsion sides of the two plates together, and they are perfectly safe until you are ready to develop them.

Many photographers hold a plate on one hand while dusting the emulsion side This is all right if the plates are handled correctly afterwards. But a slight trace of perspiration or chemical impurity on the hands where they touch the backs of the plates will remain on the glass.

Such marks from handling do no harm if the emulsion sides of the plates are always packed together, but if one plate goes into a box, emulsion side down, and the next plate the same way, the emulsion side of the last plate comes in contact with the finger marks on the glass side of the first plate, and these marks are sure to offset on the emulsion and show, when the plate is developed. Often there are distinct finger marks, but at times, only irregular opaque blotches. Bare hands never come in contact with either surface of a plate in manufacturing or packing, as employees wear clean gloves and the plates are handled entirely by the edges. And they are always packed in the boxes face to face and back to back. Handle them the same way in your dark room and you will not have any trouble from finger marks.

From An Eastman Portrait Film Negative.

From An Eastman Portrait Film Negative. By Wilfred E. Smith Matzene Studios, Chicago.