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.
Combination Prints. There are times when prints are wanted mounted in sets of from three to six in a row, and in order to mount them so that they may be folded together, a squeegee plate as long as the combination required, is necessary. These large plates are made to order only, and can be purchased from any photographic supply house. To mount the combinations, first clean the plate well and, having previously sorted the prints and numbered them in regular order as they are to appear in the set, lay them within a quarter inch of each other on the plate, squarely adjusting them upon it in a straight line. Expel the surplus water with the flat squeegee and then roll them in contact with the print-roller or the large metal roller. With this done, paste the entire set; then cut narrow strips of muslin, about one inch wide and a little longer than the width of the print, and lay them over the joints of the prints, after which paste the strips and then back the prints with the regular backing and stand the plate up to dry. When dry, the print can be peeled off the plate by catching hold of one corner and gradually lifting on the print.
Paraffining The Plate. Should the prints stick to the plate, the latter should be prepared with paraffine, which will overcome this difficulty. First wash the plates with warm water, carefully removing all the paste; then mop off with blotters and allow to dry. When thoroughly dry, with a tuft of cotton swab the plate with the following solution:
In the absence of the above solution a drop or two of castor oil may be substituted. It should be well rubbed in with absorbent cotton, and the plate then rinsed with clean water.
291. The plate is thoroughly swabbed with this solution and then polished with a tuft of dry cotton, rubbing all the superfluous solution from the surface, making it perfectly smooth and clean, when the plate is again ready for more prints. Plates should be polished with the above solution after using half a dozen times, to insure the prints not sticking.
Trimming Prints. After the prints come from the plates they should be trimmed and squared accurately. This can be done either with the regular trimming board or by means of a sharp knife, using an ordinary metal square for a guide. After prints are squared, if they are to be used loose, all the corners should be rounded. This is done with a pair of large shears. Where the prints are to be used as leaves in a book only the two outside corners should be rounded.