PRINTING ON GELATINO-CIILORIDE PRINTING-OUT PAPER.
the latest development of silver printing, has now become exceedingly popular, and by most amateurs is pre ferred to the albumenised paper process just described. It possesses one great advantage over the latter process, which is that the surface of the print can be rendered at will either glossy, or "matt," as a surface devoid of glaze is termed. It is also slightly more sensitive, and consequently prints quicker than ordinary albumenised paper ; at the same time it is quite as easy to manipulate.
There are several different makes of printing-out paper to be obtained from the dealers ; they are all reliable, and the reader will probably succeed equally well with either. The first papers of this kind introduced commercially into this country were Obernetter's rapid printing-out paper and Liesegang's Aristotype ; both of these are of German make. Then, under the supervision of Mr. Woodbury, an English firm brought out a similar paper under the title of Celero type, which was followed later by the Ilford Company with their "printing-out paper." My advice to the amateur would be to select any one of these papers, and keep to it until perfect results can be easily produced.
So far as the actual printing is concerned, the operations are carried out in precisely the same way as when using ordinary albumenised paper. But gelatino-chloride paper being, as I have said, more sensitive, greater care must be taken, both in filling the frames, and in examining the prints, to avoid degrading the purity of the whites by unduly exposing the paper to the action of light. Negatives which are rather thin will give the best prints, and if the weather is at all damp a piece of india-rubber cloth may be used as a backing instead of the blotting-paper pads previously recommended. The paper will be found to print much quicker than albumenised paper, and the frames will, con sequently, require to be more closely watched. Neither will it be necessary to over-print to such an extent as is required when using ordinary albumenised paper, there being less loss in the subsequent operations of toning and fixing. If the prints are to be finished off with a matt surface, they should be less heavily printed than if a glazed surface is desired.
The prints may then be toned, either with a toning bath containing sulphocyanide of ammonium, and subsequently fixed, or the operation of toning and fixing may he per formed together by using what is called the " combined bath," which is a toning bath containing sufficient hypo sulphite of soda to effect the fixation of the prints at the same time as the process of toning is going on. This latter mode of working is not, however, one that can be recom mended to a novice, for unless certain precautions are observed the prints may be liable to fade. This is partly due to the fact that the bath will sometimes continue to tone the prints after all the gold has been exhausted, and, to a novice, this would be perplexing, for such action isdue to what is called sulphur toning, and prints so toned are extremely liable to fade. Notwithstanding this weakness,
the combined bath, when properly used, gives most beautiful results, and if the bath be not overworked, and if the prints are thoroughly washed after fixing, fading of prints is not very likely to ensue.
When the operations of fixing and toning are to be carried out independently, the toning bath may be made up as follows :--Dissolve 30 gr. of sulphocyanide of ammonium in 16 oz. of water, and add, subsequently, 2 gr. of chloride of gold. The bath should be allowed to stand twenty-four hours before it is used.
The procedure is similar to that laid down for the treat ment of albumenised paper. Upon removal from the printing frames, the prints will require to be washed, preliminary to their being placed in the toning solution, in order that the mareduced nitrate of silver may be got rid of. Here a word of caution becomes necessary, for the sensitive surface, being composed of gelatine, is far more tender than the comparatively tough film of an albumen print, and requires, therefore, much more careful handling. The prints should be placed in the washing water one by one, and completely immersed by pressing them below the surface, so that air bubbles may not form on the surface, which would probably cause markings on the finished print. The washing water should be changed several times, or until it ceases to appear milky. The toning bath having been poured into a dish, the prints should be removed from the washing water and placed in the toning solution. Too many prints should not be toned at the same time, as the toning action is sometimes very quick, and it will be difficult to remove the prints before they over-tone. They must also be kept in motion, and not allowed to lie still, or unequal toning would result. The best way to do this is to lift them up and turn them over with a small pair of ebonite forceps, which may be obtained at a dealer's for 6d. This is better than dabbling in the solutions, which should always be avoided. When the prints first go in the bath they will turn a rusty brick-red colour, but will soon begin to tone, going through all shades of reddish brown and chocolate to purple. When they reach a tone a little darker than the desired colour they should be at once withdrawn, and transferred to clean water, when they may be washed in the manner described for silver prints. The toning bath, after it has been used, should not be returned to the stock bottle, but should be kept separate, and may be used again, with the addition of a little fresh gold solution, until exhausted. The prints are then transferred to a freshly made hypo. bath, consisting of hyposulphite soda 3 oz., water 10 oz., in which they are allowed to remain for ten minutes, after Nvhich they may be placed in the washing tank.