Varnishing And Mounting Phototype Prints Printed Without Margins. Phototype prints that are to be mounted on card- or bristol - board, may be allowed to retain their mat appearance, or they may sometimes be varnished to give them more transparency and brilliancy, and more often to assimilate them in appearance with the ordinary photographic prints. In the first case, it suffices to trim the edges of the prints and stick them with paste on their final support, which has been previously dampened, so that they will dry evenly and without cockling. "When sufficiently dry, the sheets are passed through rollers so as to incorporate the print with the board, and to obtain a polished surface. By this means the phototype print acquires more solidity, and the ink is less liable to rub off by friction. It is a kind of fixing. The polishing should not be done until the fatty varnish becomes sufficiently hard and dry to resist the pressure of the rollers. The prints to be varnished may be of two kinds, according as they are printed on laid or unlaid paper. If the paper is laid or albu-memzed (to be afterwards coagulated), it may be varnished at once, without having to fear that the varnish will penetrate the paper. But if the paper is not covered with a protecting coating, it is indispensable to gelatinize it before using the varnish. The gelatinizing is done with a brush, using a tepid solution of ten per cent, of white gelatin in one hundred grammes (three ounces two drachms) of ordinary water. The gelatin is evenly spread with a large flat brush, avoiding air-bubbles as much as possible. With a little practice this operation is easily learned. The gelatinized prints are stuck with thumb-pins, two together and back to back, on strips of wood edged with cork, and when dry are varnished. The best varnish to be used is that which, whilst remaining white, is capable of giving a hard coaling, and one difficult to scratch. We prefer white gum-lac dissolved in methylic alcohol at fifteen per cent. When the gum-lac is placed in alcohol, it will be remarked that the solution is rendered turbid by fatty substances held in suspension. If, as indicated by Mr. Peltz, powdered lime be added, we obtain a solution three-fourths of which are limpid, and what remains filters rapidly even through a felted cloth. We can also use one part essence of it improves their appearence. As has been explained, the prints may be supplied with a margin of white paper, or they may be trimmed and mounted the same at photographs. If the latter operation is to be percare must be taken that no moisture strikes the surface of the prints, lest they be soiled and spoiled petroleum or benzine fur three parte of varnish. Two strata are formed: the first contains the fatty matter which it thus eliminated. It is well to separate the fatty body, otherwise filtrs-tfoa is very slow and the varnish lacks brilliancy. This varnish is carefully put on with a tuft, so as to avoid air-bubbles, and as soon as the print is coated it is placed in especial drying-box, represented by Fig. 108. This consists simply of a rectangular, sheet-iron box, about 1 meter (391/2 inches) in length, and meter (10 inches) in height. A gas - tube, pierced at distances of from 6 to 8 centimeters (2 5/12, to 3 1/6 inches), extends the whole length of the upper portion of this box, whose front is open at two - thirds of its height; a wire- cloth separates the upper third portion from the other two, forming the interior partition of the chamber through which the grating extends. The front partition of this chamber is provided with hinges, in order to light the burners. The plates are placed in the lower open portion, resting on the bottom. The varnish dries rapidly and the wire - cloth prevents the volatilized alcohol from taking fire. With an apparatus of this kind it is possible to varnish very rapidly a great number of prints. Nothing more remains to be done than to trim them and stick as usual. Care must bo taken, however, to avoid destroying, i n a measure, the appearance of the varnish by the swelling of the paper, to not wet it too much with the paste, and especially to not allow it to remain too long a time with the back covered with paste before mounting. After drying, polish as has been explained above. To avoid gelatinizing, we might, after the prints are sufficiently dry, pass them separately over the surface of a liquid thus composed:

Fig. 108

361 Varnishing And Mounting Phototype Prints Print 130

Water,.......................................................

500 grammes (16 Troy ozs.)

Borax,..........................

130 " (4 " 1 dr.)

White Gum - Lac,..........................

100 " (3 " 2 drs.)

Carbonate of Soda,..........................

6 ( 1 1/2 " )

Dissolve the borax and carbonate of soda in boiling water, and add the white gum-lac by small bits; filter with care. The prints passed in this bath, when cold, are stuck in pairs, back to back, on strips having points for the purpose, and when dry they may be varnished with the aid of heat. In this manner there is nothing on the surface of the image but gum-lac, without the interposition of an organic matter, such as gelatin, liable to become soft by dampness, to mould and injure the paper, and consequently the image that it carries. In winter it is best to wet with the gum-lac in a rather warm room, and the bath itself should be

362. The fugitiveness of silver salt prints, such as have been considered in Lessons M to S and W, has compelled a great deal of research and experiment to find a process by which unfading prints could be made. The carbon process has had a long trial, but has not succeeded in getting much of a foothold. The Woodburytype process is a most ingenious one, kept at an average temperature of from 16° to 20° C. (59° to 68° F.). It is also possible to stop the pores of the paper, which is to he varnished, by a slight parchmentizing. To do this, prepare a mixture, cold, composed of

Water,..........................

1 part.

Sulphuric Acid,......

2 parts.

The sheets are immersed for a very few moments in this mixture, and then rapidly plunged into a great quantity of cold water. To completely neutralize the effect of the acid, washing may be finished in a dish containing water to which a small quantity of ammonia has been added. To avoid cockling, the parchmented paper should be dried under pressure, on by stretching the sheets upon frames. This mode of preparing the paper may suit in certain cases owing to the diaphanous appearance which it gives to the paper - very pleasing in some kinds of prints. Care must be taken to avoid pushing too far the action of the acid. It is sufficient to obtain the effect on the surface of the paper. The varnish will always re-main on the parchmented surface, but it should be put on whilst the image is stretched, so that the heat necessary for the varnishing should not cockle the prints and render them unfit for mounting. - Leon Vidal.