848. No. 1. Bleaching Stock Solution.-

Ferricyanide Potassium............................

2 1/2 ozs.

Bromide Potassium......................

2 1/2 ozs

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

.. 60 Ozs.

849. No. 2. Re-Developing Stock Solution.-

Sulphide of Soda............................

2 1/2 ozs.

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

..30 ozs.

850. Prepare the bleaching bath as follows: Of Stock Solution No. 1, take 4 ozs., water, 4 ozs., aqua ammonia 4 drops.

851. Prepare your re-developing bath as follows: Of Stock Solution No. 2, take 1 oz., and water, 8 ozs.

852. Pour the 8 ozs. of bleaching bath into a tray no larger than is absolutely necessary to hold the prints. This tray must be used for no other solution. Pour the 9 ozs. of re-developing bath into another tray, which must never be used for any other purpose than to hold the redeveloping bath.

853. Manipulation

Manipulation. First immerse the print in the bleaching bath. Allow it to remain until but faint traces of the half-tones are left, and the black of the shadows has become weak. (The image will then clearly resemble an undeveloped platinum print.) This will require about one minute. Next rinse the print in fresh water and place in re-developing solution.

854. Allow the print to remain in this solution until all of the original detail has returned. This will require about 20 to 30 seconds, after which the prints should be washed thoroughly. A large variety of sepia tones can be reproduced in this way. The warmth of tone is governed principally in the bleaching bath. For example, a print bleached so there is almost nothing left, will be of different tone than a print bleached but slightly. Judging the exact amount of bleaching can only be acquired by practice. Of course the quality of the negative has much to do with the depth of tone. A soft negative will give a warmer tone than a hard, contrasty one. A hard, contrasty print should be bleached farther than a soft print.

855. Prepared Re-Developing Solutions

Prepared Re-Developing Solutions. For those who do not care to prepare their own chemicals the prepared re-developing solutions can be obtained from the manufacturers, or any dealer in photographic supplies. One fifty cent package of re-developer will enable one to re-develop three hundred 4x5 prints, or their equivalent. The prepared solution is generally put up in a concentrated form, consisting of a box of fourteen capsules and a bottle of solution. Each capsule contains chemicals, which require only the addition of a certain quantity of water and a few drops of aqua ammonia to make a bleaching bath for the reduction of the print before re-development. The liquid contained in the bottle is highly concentrated and should be used carefully. It is important that the prints should have been thoroughly washed so that no trace of hypo remains before re-developing them.