This section is from the "Studio Light Incorporating The Aristo Eagle - The Artura Bulletin 1913" book, by Aristo Motto. Also see Amazon: Studio Light Incorporating The Aristo Eagle - The Artura Bulletin 1913.
We have mentioned in previous articles on this subject, the necessity for securing in the negative as full a scale of gradation - as much roundness and brilliancy as one expects to secure in the print. A series of exhaustive experiments which we have recently conducted, have proved to our entire satisfaction that this quality can be secured by tank development as readily as by the tray method. But these experiments have also demonstrated the necessity for a slight variation of the developer for the faster brands of plates.
These experiments have given us a formula which is in every way far superior to that previously recommended, and a trial will convince the owner of a tank that with this improved formula, varied to suit the speed of the plate used, a failure can only be attributed to local conditions of water.
For this reason, we would recommend that a trial be made with distilled or pure rain water and the result compared with that secured by using water from the local supply. If the last experiment gives negatives with more color than the first, the sulphite may be slightly increased. If there is less color, the sulphite may be slightly reduced, always bearing in mind that the first result, secured by using pure water, is the result that gives the best possible printing quality.
We are all looking for a means of securing the best results, and as manufacturers of plates, we are especially pleased with the result of our work with the following formula:
Water.......16 ozs.
Metabisulphite of Potassium 70 grs.
Pyro........1 oz.
Bromide of Potassium . 8 grains.
Water.......16 ozs.
C. K. Co. Sulphite of Soda 13/4 ozs. (or Hydrometer Test 55)
Water.......16 ozs.
C. K. Co. Carbonate of Soda 1 1/4 ozs.
(or Hydrometer Test 40)
To develop use:
A........ 2 1/4 ozs.
B........ 2 1/4 ozs.
C........ 2 1/4 ozs.
Water...... 58 ozs.
Temperature 65 degrees. Develop 15 minutes.
(Such as Seed and Royal, S. E. R.) use:
A......... 3 ozs.
B......... 3 ozs.
C......... 3 ozs.
Water....... 55 ozs.
Temperature 65 degrees. Develop 15 minutes.
To develop use:
A........ 5 1/2 ozs.
B........ 5 1/2 ozs.
C........ 5 1/2 ozs.
Water...... 140 ozs.
Temperature 65 degrees. Develop 15 minutes.
(Such as Seed and Royal, S. E. R.) use:
A........ 7 1/2 ozs.
B........ 7 1/2 ozs.
C........ 7 1/2 ozs.
Water...... 134 ozs.
Temperature 65 degrees. Develop 15 minutes.
There has been such a popular demand for the Eastman Mask Chart, announced in the June Studio Light, that it has been necessary for us to make this chart in 11 x 14 size. Printers who have used these charts for cutting masks have found them so accurate, convenient and such great time savers, that in many studios they are being used exclusively for masking negatives where white margins are desired on the prints. The 11 x 14 Mask Charts are put up in packages of one dozen each, and may now be had from your dealer. The 11 x 14 Mask Charts list 30 cents per dozen.
 
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