Water............................................................................. 10 ozs.

Metol....................................................................... 7 grs.

Sodium Sulphite, crystals pure.............................................. 1/2 oz.

Hydroquinone............................................................... 30 grs,

Sodium Carbonate, desiccated..............................................200 grs.

(Or 400 grs. of crystallized carbonate.) 10 percent Bromide of Potassium solution, about.....................10 drops

Amidol. Water.................................................................... 4 ozs.

Sodium Sulphite, crystals pure..............................................200 grs

Amidol, about................................................................ 20 grs.

10 per cent Bromide of Potassium solution, about.......................... 5 drops.

If blacks are greenish, add more amidol; if whites are grayish, add more bromide of potassium.

Be sure to have your chemicals pure, especially your sulphite and not to let your developer become spoiled by oxidation; therefore, keep it in small, well-stoppered bottles filled to the neck. Rubber stoppers are recommended. Too weak a developer, or one that is oxidized or contains too much bromide, will give greenish or brownish blacks.

It is almost invariably necessary in order to prevent foggy or stained whites in prints, to add a small quantity of a ten per cent bromide of potassium solution to the developer. This quantity will vary according to purity of chemicals and water and according to the age or the condition of dryness of the paper. "Special Velox" can stand more bromide in developer and further dilution of same than ordinary Velox without giving greenish blacks.

The developing can be done a few feet from the open ruby lamp but we prefer to be safe and use red light Develop as directed for bromide papers, wash slightly and fix in the following bath:

Hypo........................................................................... 16 oz.

Water........................................................................... 64 oz.

Then add the following hardening solution:

Water......................................................................... 5 ozs.

Sodium Sulphite Crystals.................................................... 1/2 oz.

Acetic Acid No. 8 (or 4 1/2 deg. B.)............................................ 3 ozs.

Powdered Alum............................................................... 1/2 oz.

This hardening solution can be left out but the surface of the prints may then remain rather soft and the hypo bath will soon discolor and is then liable to stain the prints. With the hardening solution this mixture keeps perfectly clear and can be made up at any time in advance. It can be used as long as it is strong enough. It is also an excellent fixing bath for dry plates.

Rodinal and Tolidol also make good developers for all kinds of Velox and Bromide papers and especially fine results are to be obtained with Tolidol. With the lattei, which is a comparatively new developing agent, used for dry plates, films and developing papers, special formulas and directions are given for developing the various kinds of papers.

Platinotypes

There are two kinds of platinotype paper on the market, one made by Willis & Clements, Philadelphia, and the other made by John Bradley, Philadelphia. Both papers are good.

There is an indescribable soft and pure tone about a platinotype picture which is not found in other papers, but which is somewhat approached in Aristo-Platina, Velox and Carbon papers. This paper must be kept dry and at the same time cool and comes in prepared tubes. These tubes should be kept in the ice box when not in use.

Printing

This paper requires about one-third the exposure of ordinary printing-out paper and a properly printed sheet will show only a faint brown image on the yellow surface of the paper. The printing frame must be thoroughly dry and a sheet of thin vulcanized rubber should be placed on top of the paper in the printing frame before placing the back in position. Dampness of the back of the printing frame or in the paper, will cause muddy-looking prints and impure whites. The paper should be printed until all parts of the picture are visible except the high lights and the printing must be examined by subdued light only.

Developing

The manufacturers of these papers provide developing salts and these are dissolved according to the accompanying directions and kept as a stock solution. The prints should be developed as soon as convenient after printing and if for any reason the developing cannot be proceeded with at once then the prints should be returned and kept in the tube until such time as it is convenient. These papers are developed either in hot or cold developer but in either event the work of development should be performed in the dark room, or by gas light. The solution being ready, the print is floated upon it, exposed side down, for about thirty seconds. Dishes made of porcelain or agate ware should be used for development. After the print has floated upon the bath for fifteen seconds, face down, it may be turned over in order that you may the more readily note the development as it progresses. When the print has developed to the right degree action is stopped by plunging it into the acid clearing bath, which will be described. Before developing the next print, stir the bath in order to break up any scum which might be left by the first print.

The developing bath should never have a lower temperature than 6o° F. or it may be warmed by means of an oil or gas stove to 100° F. but never above this point. A warm developer, as a rule, gives warmer tones and under exposed prints may often be saved by using the developer at 100° F. The developer is not to be thrown away after use but should be poured in a separate bottle and marked "old platinotype developer" and with the addition of about ten per cent of fresh developer can be used on the next batch of prints. The developer should not be filtered but should be kept in a dark corner in the dark room. A little cloudy matter in the developer does not affect its use and it clears up materially while standing. You should always have at least a half inch of developer in your tray when developing.