This section is from the "Studio Light Incorporating The Aristo Eagle - The Artura Bulletin 1922 " book, by Aristo Motto. Also see Amazon: Studio Light Incorporating The Aristo Eagle - The Artura Bulletin 1922 .
THERE is always a demand for something new and novel in photography, and while the process of making Doretypes is not a new one, there are apparently many photographers who have never made them.
The requests we have received for the instructions given several years ago for the making of Doretypes indicate that this style of picture is still in favor.
For the information of those who have never made a Doretype we will explain that it is a positive image on glass or film and that it receives its brilliancy from the material which is used to back it up.
The backing may be a fine gold bronze, a tinted paper or a light shade of silk or satin, but the material most generally used is gold bronze.
As the Doretype backing is opaque and its brilliancy must be reflected, a dark material can not be used for backing. Neither can the positive image be a heavy one. The first requirement is a clear, thin positive from a negative of good quality.
From large negatives these positives should be made by reduction, as the most attractive Doretypes are small in size.
Use a Commercial Film or a Seed 23 Plate for making the positive, give full exposure and soft development so that the image will be full of detail but quite thin.
If you must work from a flat negative, use a contrast developer. If the negative is contrasty use a soft developer, while if you have a well balanced normal negative, a normal developer will answer. The positive must be thin to give the best result.
When the positive has been developed, fixed and thoroughly washed, it should be re-developed in the re-developing solution recommended for giving sepia tones on Eastman Bromide papers. The formula is as follows:
Potassium Ferricyanide.............. 5 ozs.
Potassium Bromide 5 ozs. Water........... 120 ozs.
Sodium Sulphide. . . 5 ozs. Water............ 60 ozs.
Prepare bleaching bath as follows:
4 ozs. Water............ 4 ozs.
Prepare re-developer as follows:
1 oz. Water............ 8 ozs.
The positive is immersed in the Bleaching Solution until only faint traces of the halftones are left and the black of the shadows has disappeared. This will take about one minute.
Portrait Film Negative, Artura Print By M.A.Grady Seattle, Wash.
The positive is then rinsed thoroughly in clean cold water and placed in the Re-developing Solution until the original detail returns, which will require about thirty seconds. Rinse thoroughly and then immerse for five minutes in a hardening bath composed of one ounce of the following hardener to sixteen ounces of water.
Water............ 5 ozs.
E. K. Co......... 1 oz.
No. 8 Acetic Acid
(28%)............ 3 ozs.
Powdered Alum ... 1 oz.
The re-developed positive is thoroughly washed and dried and very carefully spotted. It is now ready for backing unless it is to be colored. If colors are to be used they should be transparent colors such as are made from Velox Water Color Stamps. Too little color is preferable to too much and the tints should be very carefully blended. A delicate tint against a light background will be found most pleasing.
If silk is to be used as a backing, only the lightest shades and finest textures will be found suitable. If tinted papers are to be used an enameled or very smooth surface is best.
Lay the positive on the material to see the effect. It is best to make several positives of the same subject in your first experiment so that you can determine by comparison what strength of positive will give the most pleasing result. The standard selected can then be followed in future work.
When silk is used as a background it should be backed up with cardboard, cotton and paper. Cut a piece of cardboard the size of the positive, lay a piece of cotton batting over the cardboard, cover the cotton with a heavy sheet of white paper and place the silk over this. Lay the positive on the silk, being careful not to wrinkle it, and passepartout the positive and backing together. By applying a slight pressure while binding, the cotton will hold the silk in good contact with the positive.
The most common and generally used method of backing is to coat the film side of the positive with gold bronze. It is necessary to use care in selecting the bronze powder as these pictures are often quite small and a coarse grade of powder will give a coarse grain to the picture.
A dark gold bronze gives a dull effect that is not pleasing. Use a very fine, natural gold-color bronze that will give a smooth surface. In most cases your stock house can supply you if you will specify "Light Gold Photo Coating Powder."
This powder must be combined with a liquid that will not affect the silver deposit or the gelatine and that is as nearly colorless as possible. The best thing we have been able to find for liquifying bronze powder is Eastman Lantern Slide Varnish. It is colorless, dries in about thirty minutes and does not affect the silver image or the gelatine.
Portrait Film Negative, Artura Print By M. A. Grady Seattle, Wash.
Use a small amount of the bronze powder and add varnish until the mixture is about the consistency of thin paint. Apply it to the film side of the transparency with a flat camel's hair brush about an inch wide, and allow to dry with the transparency lying perfectly flat. If the bronze shows brush marks when dry it has been applied when too thick. The solution should be thin enough to flow together, should be applied quickly and should not be gone over, once the entire surface has been covered.
With this method the finished picture should also be backed and the edges bound to protect it from moisture. If the positives have been properly handled, the results will be as permanent as the silver image itself.
To give a Doretype the proper setting it should be placed in one of the leather cases made especially for Doretypes. The case gives it the necessary tone and enables you to ask a price consistent with the work you have placed on its production.