CHAPTER III.PAPER TRANSFERS—(Continued).

Prepare a solution of

Gelatine5ounces.Sugar1ounce.Water20ounces.

Soak the gelatine in the water (cold) until quite soft, then melt it by the application of heat (nothing is better for this sort of work than aBain Marie, a domestic utensil with a porcelain pan enclosed in one of tin); then add the sugar and stir well, continuing the application of heat until a temperature of 150° F. has been reached; now strain the gelatine through muslin, into a clean dish placed in a larger dish containing boiling water, the heat from which will keep the solution of gelatine in a properly liquid state during the operation of coating the paper.

The best for these transfers is a good hand-made writing paper, or good bank-post.

Cut the paper into suitable sizes, leaving a little extra margin at one end, and float it upon the hot gelatine solution as above; be careful in laying the paper upon the gelatine, that air bells are avoided; when the sheet is laid upon the surface, raise it rapidly, and throw it at once over a cylinder of cardboard or of wood, and at once commence to revolve this cylinder rapidly, first in one direction, and as the limit of the length of paper is reached, revolve it in the other, which motion will alternately bring first one end uppermost and then the other. By this means an even coating of gelatine upon the paper is secured, which is not possible when the paper is hung up by clips directly it is taken from the surface of the hot gelatine. The cylinder is kept revolving until the gelatine has set, when it may be hung up to dry upon clips, or laid face up, over a line upon a piece of cardboard; during the operation of revolving the cylinder, any air bells formed in the gelatine coating may be removed by blowing or pricking them.

This, to my mind, is a most elegant method of coating small sheets (up to thirty inches long) with a coat of gelatine, for which I willingly give the{137}Royal Engineers the credit, it having been demonstrated to me by Ex-sergeant Dalton, of that corps.

Paper coated in this manner, when dry, is ready for sensitizing; but if coated in the ordinary manner, it should, when dry, be coated a second time and hung up to dry in the opposite way that it was the first time.

Paper coated with gelatine solution as above, may be stocked, as the coating does not deteriorate with time; but the operator must be careful not to allow the solution of gelatine to get below 125° during coating, else the surface will be sticky. The temperature of the drying room must not exceed 70°, in fact, 60° will be best.

Paper so coated is sensitized by immersion for three minutes in

Bichromate of Potash2ounces.Water50ounces.

In hot weather this solution must be kept cool with ice.

When the time of immersion has expired the paper is removed, and laid face down upon a sheet of glass free from scratches—which sheet of glass has been well polished with finely powdered talc (or French chalk)—now squeegee the back of the paper vigorously, to remove the superfluous solution and bring the surface of the paper into absolute contact with the glass plate. The sheet of glass is now placed in a rack, in the dark room, until the paper is quite dry, when it may be readily stripped off the glass, and is ready for printing the transfer. The operation of drying should be done in a current of air at a temperature of about 60°, and the paper must be quite dry before attempting to strip it from the glass.

The exposure under the negative is the same as described in the previous chapter.

When sufficiently exposed, the print is removed from the frame in the dark room, and at once immersed in cold water, where it is allowed to stay for five minutes, when it is withdrawn and laid upon a piece of plate glass, or a zinc plate, the face being uppermost; then the loose end of the paper (provision for which must be made in cutting the paper) is tucked under the plate, so as to hold the transfer in position in the subsequent operations.

Now take a glue roller (the same as used for inking up the albumen image on zinc, described in Part I., Chapter IV.), and having spread a little of the ink described in the last chapter (chalk, litho. ink, and mutton fat) upon the slab, charge the roller carefully with a thin coating of ink, and then, having{138}removed any moisture from the face of the transfer with a soft sponge, apply the inked glue roller, rolling one way only—i.e., from the body (presuming that the edge of paper tucked under the slab is next the body of the operator); continue rolling until the whole of the lines forming the picture are coated with ink, and the whites quite clean and free from ink. If the roller should get wet from water oozing from under the transfer, wipe it with a damp cloth and then roll it a few times on the inking slab, and continue rolling the transfer. Be careful that the portion of the transfer representing the whites of the picture has absorbed its full modicum of water before beginning to roll up, and also that there is not too much ink upon the roller. When the transfer is successfully inked up, it is hung up to dry, and when dry is trimmed to size, placed in a damping book, and transferred to stone.

The exposed transfer, after wetting, and being placed upon the plate of glass, or zinc, may be developed in another way. First remove the superfluous water from the surface with a soft damp sponge, then rub it gently all over with a pad of cotton-wool dipped in a thin mixture of ink thinned with turpentine and well mixed with a palette knife (this ink should be a little thicker than ordinary copying ink); all the image must be covered with the ink. The turpentine is then allowed to evaporate, when by rolling with the glue roller from the body, the ink will clear away from the whites, leaving the lines sharp and distinct. Do not use too much pressure, else the ink may be removed from the lines, in which case cover the whole picture with a fresh coat of the thin ink, and again roll off. The subsequent operations are the same as for the other paper transfers.

The ink for this method is made by melting over a Bunsen burner, or paraffine stove,

Chalk Printing Ink4ounces.Beeswax1⁄2ounce.Stearine1⁄2ounce.Resin3⁄4ounce.

When these are melted and well stirred together, set the mixture on fire and allow to burn for three minutes, then extinguish by putting the cover on the pot or pan, then pour it into a tin. When cold it is ready for use.

In handling the sensitized gelatine paper for transfers, every care must be exercised to keep the paper from being exposed to the action of light, before and after exposure in the printing frame, else there will be great difficulty in getting clean transfers.

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