733. "Nepera" Developing Solution. - This is known as the universal developer because it may be used not only for Velox, but for Argo, bromide paper, films or plates. Like all "Nepera" liquids, it is a concentrated solution with combination of purest chemicals which will give the best results. It differs from "N. A." Velox Liquid Developer in that it does not possess the non-abrasion and fixing guide properties; but on the other hand, when used in combination with "Nepera" capsules, four of which accompany each 4 oz. bottle, it is excellent for films or plates, giving negatives of the quality best suited for de-veloping-out papers.

734. Formula for Regular Velox Use:

Nepera Solution.....................................

2 ozs.

Water..........................................

4 ozs.

735. For Special Velox Solution Use:

Nepera Solution................................

Water..........................................

4 ozs.

The temperature of the bath should be 70° Fahr.

736. For Film in Tank Developer or Kodak Developing Machine Use:

Nepera Solution...............................

.1/2 oz.

Water.........................................

12 ozs.

And add the contents of one Nepera capsule and develop for 20 minutes.

737. Fixing

Fixing. There is probably no part or process of photography that is more abused than that of correctly preparing a faxing bath and properly fixing prints. To secure permanency prints must be fixed in a fresh solution of hypo. When hypo is first dissolved in water the temperature of the solution is materially reduced. It is important that the temperature of the fixing bath should be maintained as near to 50° Fahr. as possible. Probably more prints fade from insufficient fixing than lack of washing, so these points should be given attention. Have plenty of solution strong enough to thoroughly fix prints in at least 15 minutes. Always use the acid hardener in the bath, as it will overcome the tendency of the fixing bath to cause blisters and stains.

738. Formula For Preparing The Acid Hypo Fixing Bath

Formula For Preparing The Acid Hypo Fixing Bath.

Water.........................................

64 ozs.

Hyposulphite of Soda (Crystal or Granulated) ..

16 ozs.

739. When thoroughly dissolved, add the following hardening solution, dissolving the chemicals separately and in the order named:

Water..........................................

5 ozs.

Sulphite of Soda (Desiccated)...................

1/2 oz.

Acetic Acid No. 8.................................

3 ozs.

Powered Alum.........................

. 1 Oz.

740. This solution will keep well; one pint being enough to fix at least two dozen 4x5 prints. If sulphite and carbonate of soda in crystal form are substituted for desiccated, double the quantities mentioned should be used.

741. The most accurate way of preparing a fixing bath is by using a hydrometer, testing the specific gravity; 70 being the correct degree.

742. For the amateur, or those who do not care to prepare their own hardening solution for the hypo bath, we would advise the use of prepared solutions, and the concentrated Velox Liquid Hardener is especially recommended. For use take,

Water.........................................

16 ozs.

Hyposulphite of Soda............................

.4 ozs.

Velox Liquid Hardener.............................

.. 1 Oz.

743. Note

Note. Where you prepare your own Acid Hypo bath should the prints bleach or appear brown in tone, it is quite certain you are using too much acetic acid. Perhaps you are using glacial acetic acid instead of commercial No. 8. The former is very much stronger than the No. 8, and should not be used in the hypo bath unless diluted. For difference in strength see Glossary.

744. The washing and drying of prints is exactly the same as previously instructed.