Now this effect we have to avoid in mounting gelatine prints. If we simply paste a starch or other similar mountant on to the back, in the same manner as with an.
albumen print, we lose the polish at once—before, in fact, we have time to attach it to the. mount. The more liquid the mountant the stronger its action upon the gelatine film. We will first, then, consider what course to adopt to mounts the prints as they are taken off the glass. If we employ a gela tine mountant with as little water as possible it is evident that we stand less chance of spoiling the surface of the print. Take; then, z ounce of hard gelatine and soak it in water ; squeeze all the water out of possible, and dissolve. When dissolved, add 4 ounces of methylated spirit. If a large quantity be made, sufficient for some time, a small amount of carbolic acid should be added to prevent putrefaction. This mountant should be placed in small bottles, and when required, a bottle of it should be placed in a little warm water until the contents are dissolved. With a stiff brush it should be rapidly applied to the back of the print, and the latter immediately adjusted to the mount, smoothed down with a soft, clean rag, and the whole laid away, face upwards, to the air to dry. On no account should these prints be laid one on another when mounting, as they will be liable to stick confused together in a heap.
Another way is one that is adopted by a great many amateurs, who treat the edges only of the print to the mounting solution. The same mountant may be used, but with a small brush ; it is laid on round the edge of the print in a rim not more than the sixteenth of an inch. It is then attached to the mount. Instead of gelatine, a solution of indiarubber dissolved in benzole may be used, but this adherent is not a stable one. The indiarubber becomes hard after a time and crumbles away, and allows the print and the mount to become detached.
If the method of mounting round the edges be adopted, it should be done directly the pict ure leaves the glass, as after a little while the print contracts and gives a tight surface. If this be impossible the prints should be removed to a cool damp room or cellar for a few minutes pre vious to mounting. Gelatine contracts and expands in a very remarkable manner ; a very good hygroscope can, in fact; be made out of a piece of gelatine carbon tissue. It is therefore neces sary to avoid mounting the prints by the edges only if in a dry state, as when moist the print contracts and buckles up to those parts not held to the mount by the solution. Another method
I must mention, and that is the mounting of these prints behind cut-out mounts. Of course, here we can get the surface as perfect as possible, as no visible portion of the print is treated with the mountant. I think prints mounted in this manner show up a great deal better than by any other way.
We now come to the second modus operandi, in which the prints are, before mounting, treated to a support, protective backing, or whatever else you like to call it. When on the glass, and before they are perfectly dry, a piece of thickish waterproof paper is pasted on to the back. A waterproof paper can be obtained at nearly every stationer's ; this is usually white one side and coated with a black waterproof substance on the other. Cut this paper for the different prints about one-eighth of an inch each way smaller than the print itself. Apply the mounting solution to the white side, and adhere it firmly to the backs of the prints when on the glass. When dry, the prints, with their waterproof support, will leave the glass together, and they can be mounted with safety with almost any material, as the waterproof coating effectually prevents the damp affecting the gloss. This method of backing is also convenient for prints not to be mounted, as it strengthens them for handling.
If properly done, and the right sort of paper be employed, prints mounted in this manner should not lose a bit of the beauty—vulgar beauty, if you like—of their gloss.
Another method of mounting, which I have purposely left to the last, being the most diffi cult, is the following. Here we move the prints onto the mount while upon the glass, and strip off together.
The prints, when removed from the water, are squeegeed on to pieces of glass, a little larger only than themselves. When nearly dry, the back is pasted over carefully, and the picture and glass laid on the mount. Of course the print must have been trimmed to proper size before squeegeeing on to the glass. When thoroughly dry the print and mount should leave the glass. If there is any difficulty about this, a sharp knife should be inserted between the print and the glass, to give it a start. It is for this reason that the glass must not be much larger than the print.
Some operators prefer to first damp the cardboard before applying the print, so as to cause it to expand to the same degree as the latter. (See also Mount and Mountants.) For special instructions for mounting stereoscopic prints see Stereoscopic Photographs.