Toning

Albumen papers need not be printed quite so deeply as gelatine papers; the loss in the toning bath is not so great. The paper for prints from a given negative should always be cut the same way out of the sheet, because paper shrinks during the long immersion in water, and the shrinkage is always greatest in the direction of the fibre. When the high lights take on a pink tinge, and the shadows show signs of bronzing, remove from the printing-frame, wash until the milky deposit ceases to come away, and immerse in the toning bath.

Acetate Toning Bath

Gold Chloride........15 gr.

Sodium Acetate........1 oz.

Water.........20 „

For use take 1 oz. of this stock solution and make up with water to 8 oz. to tone one sheet of prints. Our own way of mixing the stock solution is to first dissolve the acetate in 10 oz. of water in a pint bottle, and drop the 15 gr. tube of gold into the bottle. A brisk shake will break the tube against the side of the bottle, and the remainder of the water may then be added. This toning bath will keep for months if protected from strong light, but must not be used within twenty-four hours of mixing. It will give rich, warm tones.

Phosphate Toning Bath

Chloride of Gold.......1 gr.

Phosphate of Soda.......20 „

Water.........8 oz.

The phosphate bath gives deep purple tones, but must be used very shortly after it has been prepared.

Fixing Bath

Wash the prints after toning in two changes of water, and then fix for ten minutes in:

Hypo.........4 oz.

Water.........20 ,,

Ammonia........20 min.

If blisters appear at any stage introduce a little chloride of sodium (common salt) into the next washing water. The subsequent washing and drying are the same as for gelatino-chloride papers.

Plain Salted Papers

There are several receipts in common use for sizing and sensitising these home-made papers. A good pure unsized paper, free from all traces of iron, must be taken for the foundation, either Whatman's, Saxe's, Rive's, or Joynson's. Float on one or other of the following sizing baths:

(1) Gelatine.........120 gr.

Ammonium Chloride ...... 200 „

Water.........20 oz.

The gelatine is first swelled in cold water; then the remainder of the water is added warm with the chloride, and heat applied until the gelatine is dissolved.

(2) Gelatine......... 20 gr.

Sodium Chloride . . . . .... . 30 ,,

Water......... 5 oz.

(3) Arrowroot........ 90 gr.

Ammonium Chloride...... 60 „

Water......... 10 oz.

Make up the arrowroot into a paste with an ounce of cold water, and dissolve the rest with the chloride in hot water. The paper must be floated for three minutes on one or other of these sizing baths while they are still warm, and then hung up to dry.

Sensitising Bath

This may be either the bath given for albumenised paper, which will be the best for use with sizing solution No. 1. But almost equally good effects can be got with those given below.

(1) Nitrate of Silver.......90 gr.

Water.........2 oz.

To which sufficient ammonia has been added drop by drop until the precipitate at first formed has been redissolved.

For Keeping Purposes

(2) Nitrate of Silver....... 100 gr.

Citric Acid......... 30 "

Water......... 2 oz.

Distribute the sensitising solution evenly over the paper with a broad camel-hair brush, or float in the manner given under albumenised paper for three minutes. Then dry in the dark.

Porous papers require rather more gelatine (say one-third more) than hot-pressed papers. These plain, salted papers tone well in the sodium-acetate bath given above, but the best effect, especially with drawing papers, is obtained with Clarke's platinum-toning formula:

Potassium Chloroplatinite . . . . . . 10 gr.

Nitric Acid........5 min.

Water ..........25 oz.

The fixing bath may be the same as that given for albumen paper. Combined toning and fixing baths (which we do not recommend with albumen) work fairly well with these papers.

Resinised Papers

The late Mr. Henry Cooper communicated to Sir W. Abney a printing process, the results of which have a character of their own, lacking the gloss of albumen. If printed deeply and toned in acetate this paper has almost the appearance of fine old porcelain. Coat with the following:

Frankincense........ 10 gr.

Mastic......... 8 „

Calcium Chloride....... 8 "

Alcohol......... 1 oz.

The sensitising bath consists of 6o gr. silver nitrate to the ounce of water, with as much gelatine added as it will bear at 6o° Fahr.

Self-Toning Papers

Several papers of this class have been placed on the market during the last few years, and some formulae have been published. Only the very recent brands, however, are satisfactory, either for their toning or keeping qualities, and the manner in which the gold is preserved in contact with the other ingredients is of course the makers' secret. The Paget Collodio-chloride, the Ilford Kalona, and the Kodak Solio self-toning papers will all be found good. The instructions in each case differ considerably, but as a rule such papers, after very deep printing, are placed direct in a weakly alkaline bath, and then fixed in the ordinary hypo bath, a variation in tone being obtained by a short stay in a weak solution of common salt.