US1224442A - Transferring photographic prints from separate supports to a single support. - Google Patents

Description

P D. BREW/ST TRANSFERRING PHOTOGRAPHIC PRINTS FRQTWSEPARATE SUPPORTS TO A SINGLE SUPPORT.

APPLICATION FILED JUNET, 1916.

Patented. May 1, 1917.

WITNESS M ATOM/Era tree STATES PATENT canton,

PERCY DOUGLAS BREWSTER, OF EAST ORANGE, NEW JERSEY.

TRANSFERRING' PI-IOTOGRAPHIO PRINTS FROM SEPARATE SUPPORTS TO A SINGLE SUPPORT.

Application filed June 7, 1916.

To all whom it may concern:

Be it known that I, PERCY D. BREWSTER, a citizen of the United States, residing at East Orange, county of Essex, and State of New Jersey, have invented certain new and useful Improvements in Transferring Photographic Prints from Separate Supports to a Single Support, of which the following is a full, clear, and exact description.

In a method of making photographs in natural colors which has met with considerable success the practice. is to make at least two negatives of the object, one recording the image of the object by light of one color or group of spectral colors and the other recording the image in light of another color or color-group. From these negatives (one of which is reversed from right to left) positive prints on glass or celluloid are made, which positives are then treated in any convenient manner to color or stain the images in two different colors. For example, if one negative is made through a red filter or screen, so as to record the action of light predominantly red in color, and the other through a green filter for a like purpose, the positive image from the red negative is stained green and the one from the green negative is stained red. The stained positives are then superposed face to face, in registry with each other, with the result that when the positives thus combined are viewed by white light passing through both they will exhibit the object in substantially its natural colors.

The two colored positives or transparencies described can be bound together permanently, like a lantern-slide and its coverglass, but for many purposes it is desirable to strip one of the glasses off; or even to remove both glasses and transfer the two colored films or emulsions to a flexible support, as for example opaque white paper or celluloid so that the completed picture can be handled without danger of breakage. This is especially desirable in the case of pictures of large size, say eight by ten inches and larger? The present invention relates to this feature of the process, and'its chief object is to provide a method by which the emulsions can be stripped from two or more plates without appreciable contraction or expansion of the emulsion films so as not Specification of Letters Patent.

Patented May l, 191?.

Serial No. 102,170.

to interfere with the exact registry of the two images. Another object is to provide an effective method by which exact registry of the two images can be quickly obtained. To these and other ends the invention consists in the novel process and steps hereinafter described.

In the accompanying drawing, Figures 1, 2, 3 and 4 are sectional views illustrating four stages of the process.

In practising my method or process in the preferred manner one or the other ofthe two positive plates 2, 4, is immersed in a suitable stripping solution by which the gelatin composing the film (1 or 3 in the drawing) is hardened and loosened so that it can be stripped off from its plate or support. Preferably a solution or bath of the following composition is used, at ordinary room temperature:

Solution A.

Potassium carbonate 9grams. Formaldehyde, 37% 9cc. Glycerin 900. Water 10000.

If the print is on glass, immersion for twenty minutes in the above bath will usually suffice. If it is on celluloid I prefer to immerse it for say five minutes in each of the following solutions, in success1on:

It is to be understood that wide variation in the stripping solutions used is permissible. The above solution A. works well with hammer transparency and lantern-slide plates. For other plates, formulae using sodium fluorid may be employed.

After immersion in the stripping solution the excess is wiped off. I

The other plate, previously treated in any convenient manner to harden the emulsion, as for example with the usual formalin or formaldehyde bath, is coated with a suitable adhesive or cement capable of hardening or tween 100 and 104. Preferably the plate itself is also heated to the same or slightly higher temperature to prevent too rapid setting or hardening of the gelatin layer.

The two plates are now placed face to face and shifted about with respect to each other until the two images are in registry, the operator holding the two plates be p tween himself and a source of light so as to see the work clearly. The fluid gelatin layer between the two plates permits of easy sliding movement of one plate on the other, so that registry can be secured in a few seconds; In the drawing 5 designates the layer of gelatin, and Fig. 1 shows the two plates at this stage of the process.

The two plates are now held firmly together, as by means .of a weight, to allow the intermediate gelatin layer to set. From thirty minutes to an hour will usually be found suflicient time to secure the desired hardening or setting. In warm weather. the plates can be chilled with ice. In fact strong cooling of the plates (of course after they have been brought into registry) is advantageous at any time, as it shortens the period of setting. After the gelatin has set, the plate that was treated with the stripping solution can be readily lifted off, leaving its emulsion firmly cemented to the face of'the other plate. This stage is illustrated in Fig. 2 of the drawing.

The plate bearing the two emulsions is now immersed in the stripping solution, the same solution as used before but diluted to four or five times its original bulk with water,-.1fter which it is coated with a suitable cement, for example the ten per cent. gelatin solution recommended above. The final support 6, Fig. 3, say, a piece of strong white paper or a sheet of opaque white celluloid is then pressed firmly on to the plate and the cement allowed to set, after which the paper or celluloid support 6, bearing the two emulsions 1, 3, united to each other by the cement layer 5 and -to said support by the cement layer 7, can be peeled or stripped off the plate 1 as indicated in Fig. 4. It will be observed that the print will or will not be reversed on the final support 6 according as one plate or the other was the one that was first to be stripped. Thus, if in Fig. 1 the image is seen correctly when viewed from the right of the figure, plate 2 should be stripped off first, and the image will then be correct on the final support 7 If plate 1 had been stripped off first the image on the paper or celluloid 7 would be reversed.

Any colloid or cement can be used that will set (without drying) to a suificient ex- -plate 2 was. be applied as described above.

In three-color work the third plate (not shown) is treated with the stripping solution and then cemented to the emulsion 1, Fig. 2, after which it is stripped off as The final support 6 can then It is preferable, as stated above, that one negative be reversed, right to left, with respect to the other, so that direct prints therefrom can be put in registry face to face, just as a persons hands can be put into registry palm to palm. Ifnot, a reversed image will have to be madefrom one of them or one of the prints will have to be transferred to an intermediate temporary support before applying it to the other print. In the former course, which is in general preferable, a convenient method is simply to transfer the emulsion film face down to another glass plate. Prints can then be made from it which will register with prints from the other negative.

It is to be understood that the invention is not limited to the specific details herein described, as the same can be varied without departing from the spirit of the invention.

I claim:

1. The method of treating photographic prints on transparent supports, comprising treating one of the prints to toughen the emulsion and loosen the same from its support; coating the face of such print with a suitable cement or adhesive capable of setting without drying; placing the other print,

'face down, upon and in registry with the first print and allowing the cement to set;

removing the transparent support of the first print whereby its emulsion-film is left on the emulsion-film of the other, the two forming a combined print; treating the combined print to toughen the lower emulsionfilm and loosen it from its support; and transferring the two emulsion-films to a permanent support.

2. The method of treating photographic prints to transfer the same from separate supports to a single flexible support, comprising treating one of the prints to toughen and loosen its emulsion-film; cementing the other print on the first, face to face; removing the support of the first emulsion-film, leaving the two films on the support of the second film, treating the latter to toughen the same and loosen it from its support; and transferring the two films to a permanent flexible support.

3. The method of treating photographic color prints to transfer the same from separate rigid supports to a single flexible support such as opaque white celluloid or paper,

comprising treating the first print to toughen its emulsion-film and loosen the same; cementing the other print upon the first, face to face, With a cement capable of setting without drying; removing the first support, leaving the two emulsion films cemented together on the second support, forming a combined print; treating the combined print to toughen the underlying emulsion film and loosen it from the rigid support; cementing the desired permanent flexible support to the uppermost emulsion-film of the combined print; and stripping off the flexible support with the two emulsion-films cemented to it.

4. The method of treating photographic color prints to transfer the same from separate rigid supports to a single flexible support, comprising treating the first print to toughen and loosen its emulsion film; coating its emulsion film with a cement contain- 'ing gelatin; applying the second printto the, first, face to face, and allowing the cement to set; removing the rigid support of the first print, leaving the two emulsion films on the second support to form a combined print; treating the latter to toughen the underlying emulsion-film and loosen the same from its support; coating the face of the combined print with a suitable cement; applying the desired permanent flexible support to the face of the combined print and allowing the same to adhere firmly thereto; and stripping off the flexible support with the two emulsion films adhering to it.

In testimony whereof I hereunto afiix my signature.

PERCY DOUGLAS BREWSTER.

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