Printing Photos on Any Material (Mar, 1940)
Printing Photos on Any Material
KENNETH MURRAY TELLS HOW TO SENSITIZE CLOTH, CHINA, GLASS, AND METAL
IN A NEW YORK store window a demonstrator recently attracted crowds by making photographic prints before their eyes on a variety of materials. He daubed a little solution on the surface where the picture was to be placed and, as soon as it had dried, placed a negative over it, clamped it in position with a piece of glass and a rubber band or two, and exposed the picture to the light of a photoflood bulb for a short time. The picture was then quickly developed and fixed like any ordinary photograph.
Solutions such as he was using can be purchased, but you can make your own quite easily and do stunts similar to those of this demonstrator. The process to be described is, indeed, even simpler than his. Once you have mastered it, you need not restrict your picture making to photographs on chloride or bromide paper as supplied by the manufacturers, but you can print photos directly on letterhead paper, on the flyleafs of books, or even on tissue paper if you wish, or on glass, cloth, chinaware, wood, metal, or almost any light-colored material.
The surface that is to receive the picture must first be coated with an emulsion that is sensitive to light. It is not difficult to mix suitable sensitizing solutions, provided one does not attempt to compound an emulsion as sensitive to light as are fast bromide-paper emulsions. The chances of turning out a satisfactory emulsion of that type without training and a knowledge of photochemistry would be rather slim. It is for this reason that the writer uses a very simple sensitizing formula, with which it is almost impossible to make an error or have any difficulty.
The formula is a modification of that used in making blueprint paper and gives a blue picture. If desired the blue image may afterwards be toned to sepia (brown) or black. The writer personally prefers blue because of its brilliance and unique appearance.
Ferric ammonium citrate ………… 1 oz.
Distilled water ………………………….. 4 oz.
Potassium ferricyanide, red ………………………….. 3/4 oz.
Distilled water ………….. 4 oz.
Mix an equal quantity of each of these solutions together immediate- ly before they are to be used. Apply with a bit of cotton wrapped around the end of a clean stick, and do not use a metal-bound brush. Simply swab the solution evenly over the surface of light-colored paper, cloth, leather, wood, or other material. Unless a mask is to be used in printing, the sensitized area should be smaller than the negative. The operation should, of course, be done in a weak artificial light. A yellow or red safelight is not required. Dry the surface as quickly as possible with artificial heat.
Lay a negative over the sensitized spot and hold it in place with a piece of glass to make a good contact. Thin material such as cloth and paper may be held, with the negative, between two sheets of glass. Cloth can be held flat, both for sensitizing and printing, by means of an embroidery hoop. In the case of bulky objects, bind the negative and cover glass in place with cord or rubber bands.
Make the exposure with a photoflood lamp, arc lamp, or sunlight. The latter is much faster. Continue the exposure until the sensitized surface is quite dark in an olive-green color, as seen through the less dense (shadow) portions of the negative. Test exposures may be made beforehand on paper if desired.
Development and fixing consist in merely washing- the image for a minute in water, after which the picture will stand out brilliantly. The water removes all of the sensitizing chemical that has not been affected by light. In the case of cloth and similar materials, dry the picture by pressing with a fairly hot iron.
In order to apply the sensitizer to “slick” surfaces, such as glass, metal, and plastics, the material must be coated with a thin film of gelatin. Soak one envelope of plain dessert gelatin in 3 oz. of water for an hour, then warm it until the gelatin dissolves. Apply the gelatin with a brush while it is warm, and allow it to set and dry thoroughly before coating with the sensitizer. After printing, the washing must be carried on for several minutes to remove the excess sensitizer from the gelatin.
If you wish to tone the blue image to a sepia or brown color, merely brush on a solution of 1 oz. tannic acid in 8 oz. water. Rinse the image as soon as the color is deep enough. A black color may be obtained with the same tannic-acid treatment if the image is first bleached with a very dilute solution of ammonia; 1 oz. ammonia in 16 oz. water is usually satisfactory, but as the strength of the ammonia may vary, some experimenting is advisable. Do not use the bleaching solution for any longer time than is necessary.
Blue pictures can also be toned to a sort of purple or lavender color by the use of ordinary developer of the so-called “M-Q” type (metol-hydroquinone).
When the image is lacking in contrast, it can be made more brilliant by washing with a dilute solution of oxalic acid.
Pictures applied to hard surfaces can be protected with a coat of clear, thin varnish.