266. Before albumenized paper came into use, all paper photographs were printed upon what is yet known as "plain" or "salted" paper. It is still used for enlargements, copies, and for such pictures M are to be afterwards finished by means of color, crayon, of India - ink, but is gradually being supplanted by Mr. Willis'platinum process. Brief instructions as to how such prints may be produced, will follow. Should you prefer not to salt your own paper, it can be purchased of excellent quality of the dealers, already salted, and thus some trouble is avoided.
267. The method here given is known as the ammonio - nitrate process, and la the best for the purpose. The salting solution consists of
Chloride of Ammonium,
White Gelatin, .......................
Dissolve the gelatin in the water by the aid of heat, then stir in the chloride of ammonium until dissolved; filter for use when cold. The sheets of paper should be entirely immersed in the solution, air - bubbles being avoided, allowed to remain two minutes, and then hung up to dry in a room from dust. Do not use the same clips employed for the silvered paper..
268. Silver solution for plain paper.
Pure Rain or Distilled Water, ............
Nitrate of Silver.......................
Dissolve the silver in the water, and separate three ounces of the solution from the rest, to which add liquor ammonia until the oxide of silver formed is redissolved, and the solution is again clear; then add it to the remaining six ounces of solution. Oxide of silver will again be formed, which can be allowed to settle to the bottom of the bottle and remain there until the solution is all used. This can be applied to the paper with a swab of cotton, wool, or canton-flannel. A portion of the silver solution should be filtered every time it is used, other vise there will be a marbled appearance on the paper, caused by the scum which collects upon the surface of the solution. Care should also be taken to apply the solution evenly and lightly, otherwise the surface of the paper will be roughened.
269. After silvering the plain paper it is dried by heat, and then fumed, say, ten minutes, when it is ready for printing. Great care should be exercised in handling it, as it is easily soiled and spoiled. As a usual thing, a weaker toning solution is required than for albumenized paper. A good plan is to tone the prints on this paper after the others are done.
269. To those preferring to salt their own paper, the following hints may he useful: Always remember the quality of salt has much to do with the tint of the print; the weight of the salt affects the picture in the same manner. If the bath for salting is under strength, the print will show it by a weak, bluish look, and an entire absence of the rich purplish contrasts in the face. Again, oversalting will make the printing slow and tedious, and the blacks will be feeble and of a reddish tint; measly spots are apt to show, and the whole print will appear flat and unsatisfactory. It is well to immerse some kinds of paper; but if the plain Saxe paper is used, it should be only floated, not immersed. Lay the paper perfectly flat, and lift off again with the same care as in silvering. Every printer has his own idea about the amount of gelatin needed in connection with the salting; however, this is a good medium rule; for ordinary Saxe paper, about one box of gelatin to four gallons of salting solution, in warm weather; in the winter this quantity can be nearly doubled. If the salting is done with chloride of ammonium alone, the prints will be rather brownish, and the paper will not keep so well, nor print so rapidly, as when the ammonium is used in equal proportion with the common salt. The following are the proper proportions:
Chloride of Ammonium,.......................
1 1/2 grains
1 1/2 "
Gelatin, thirty grains to the quart, in summer; in winter, use from fifty to sixty grains to the quart. - John L. Gihon.