Any bath that will tone albumenized prints will act perfectly well with plain salted papers, but to obtain a rich red brown with what are called " juicy " depths in the shadows and undegraded whites in the high lights. use the following stock solution : 15 grains Chioro-platinite of Potassium in 1‘ oz. of Water.
Then, when you have prints to tone, take from it one dram mixed with 4 oz. of water with a few drops, say 5 or 6, of Nitric Acid.
This bath will be found to tone very rapidly and it will keep fairly well. Toning being completed, wash for a minute or two and neutralize your prints in a weak bath of Carbonate of Soda, they are then ready for fixing in the usual way.
Hypo-Sulphite of Soda, - 4 oz.
Water, - - 20 OZ.
I look upon thorough fixing as necessary to ensure permanency as is thorough washing in running water afterwards, and prints should be left in the fixing bath for at least 15 minutes before they are put in the washing trough, where they remain for at least a couple of hours.
1 came across a print on plain " Saxe " paper done by my father at least 30 years ago and it is as fresh and bright as on the day it was made. It was a point with him to dab each separate print with a sponge under running water, back and front, for a considerable length of time, and I have never seen such little change in color of silver prints as are to be noticed in his.
When your prints are well washed, I take it that you have got as near to permanency as that unstable metal, silver, will allow, and although the directions for the manipulation of plain paper seem formidable enough, they are not really more so than would be required for the intelligent use and practice of any other printing-out process.
Still, for those who do not want the bother of preparing their own paper, there is one very much of the same grain and texture as platinotype, sold under the title of the " Blackfriars Matt."
I mention it with diffidence, since I am interested in it to some slight extent, but, as a matter of fact, I know of no other on the market, as that prepared by my old friend, Valentine Blanchard, has been withdrawn for some years, and another, known as " Mezzotype " which was issued by the Carlotype Co., has suffered a similar fate. With this paper, which is a chemically pure one of French manufacture, any tone, from warm red to black, can be obtained by the use of the platinum bath, and its approximate permanency is tolerably certain.
There is another method of obtaining prints on plain paper, which has been duly laid down by Lyonel Clark in his contributions to the Camera Club Journal of a few years ago, by developing an under-printed picture with a saturated solution of Gallic Acid or Pyrogallol Solution acidified with Acetic Acid. Mr. Clark also recommends the use of Arnold's pure unbleached paper in preference to any other. This is made of linen fibre instead of cotton rags and is free from chlorine or bleach in any form. Besides "Arnold " there is imitation " Creswick," which is rather more expensive, but of a fine color and texture for this kind of work. Being a heavy and thick paper (110 lbs. to the ream Royal) it requires considerably more gelatine in the sizing than Whatman, and I have sometimes found double sensitizing advantageous in obtaining strong prints.
There are again Joynson, Michallet and Ingres papers, all of which are suitable for salting, and some of the latter being in delicate tints open up new ground for photographic workers.