US773384A - Photograph on linen and process of making same. - Google Patents

Description

UNITED STATES Patented October 25,,1904.

PATENT OEErcE.

OTTO FULTON, OF OHlSWIOK, AND WILLIAM MOUNTSTEVEN GILLARD, OF TWIOKENHAM, ENGLAND.

PHOTOGRAPH ON LINEN AND PROCESS OF MAKING SAME.

SPECIFICATION forming part of Letters Patent No. 773,384, dated October 25, 1904.

Application filed April 5,1904. Serial No. 201,739. (No model.)

To (LZZ whom it may concern.-

Be it known that we, OTTo FULTON, photographer, residing at 493 High road, Ohiswick, and W ILLIAM MoUNTsTEvnN GILLARD, photographer, residing at Glen Rosa, St. Margarets Road, Twickenham, in the county of Middlesex, England, subjects of the King of Great Britain, have invented certain new and useful Improvements in Photographs on Linen and Processes of Making Same, of which the following is a specification. I

This invention relates to the production of photographs on linen or other fabrics, and has for its object to produce a picture or subject by photography on linen, cloth, canvas, or other textile or woven fabric in such manner that the effect of density will be produced by light transmitted through and the effect of brilliancy will be obtained by light reflected from the photograph produced.

The accompanying drawing, which illustrates the nature of our invention, is a diagrammatic representation in section of a duplex photograph after exposure and development.

According to this invention we take as a basis for sensitizing a white or light-colored fabric, which may be cotton, linen, silk, wool, or the like, which for brevity We may hereinafter designate the cloth. 7

The fabric or cloth hereinbefore referred to may be of any desired character. In this connection, however, we have found that 'a fabric of a closely-woven texture affords the best results, although We may employ a fabric comprising two or more series of parallel threads superposed in such a manner that the threads of one series cross the threads of the other series.

Some commercial qualities of cloth have a desirable stiffness, consistency, and translucency rendering them especially adapted to our purpose; but other kinds may advantageously be stifiened or sized. WV e prefer to do this with a weak solution of celluloid or thin celluloid varnish and in the following manture of three parts of alcohol and five parts of amyl acetate being suitable. We may in some cases apply to the cloth a coating composed of a smallpercentage of flour, starch, Whitening, or like substances for the purpose of facilitating the coating with the photographic emulsion. The cloth is saturated with the aforesaid varnish, and as the varnish dries the cloth is rolled or pressed. This is the method of hardening or sizing the cloth which we prefer; but any other method may be adopted. We coat both surfaces of the cloth with a film of light-sensitive gelatin emulsion of a kind well known to photographers or we coat one surface of the cloth with the film of lightsensitive gelatin emulsion and also prepare the body, substance, or other side of the cloth by saturating or soaking it with suitable sensitizing material. The object of this double sensitizing is twofold:

First. To combine in one effect two prints or images, this doubly sensitized material giving by one exposure what We term a duplex photograph in which are united the efiect of density by transmitted light and brilliancy by reflected light. The image at the back or either image may have its intensity adjusted by turning the cloth over and exposing the back more than thefront or the front more than the back. This may be done whether the exposure is under a negative or by means of a projection or enlarging apparatus.

Second. The gelatinous medium of the emulsion being impervious to oils serves to insulate the cloth from any oil-paint with which we may color the photograph, the said oil-paint being laid upon the gelatin surface. For this reason one side at least of'our duplex material must be coated with an impervious or gelatin coating, a condition best realized by using agelatin emulsion, although plain sensitizing and asubsequent sizing may be resorted to, and as regards the other side the use of gelatin is optional.

To facilitate the above sensitizing treatment, we, as explained above, prefer to em ploy cloth which has been previously treated with a gelatin, pyroxylin, or similar compound or which has been waxed, or we may employ a sized cloth, such as bookbinders cloth. The best stiffening or sizing method known to us and which we prefer is that in which thin celluloid varnish is employed, as already described. \Vith some emulsions we find it an advantage to size the prepared material (before coating with the sensitive emulsion) with a one-per-cent. solution of gelatin, thus facilitating the coating in aneven manner.

\Vith respect to sensitive emulsions or sensitizing preparations to be employed in our invention we may use any of the numerous sensitive preparations or emulsions well known to photographers, the one essential being the formation of a surface picture to give brilliancy by reflected light and a second image at the back of the material to give density by transmitted light.

The following are examples of the method of sensitizing the cloth for our duplex photographs.

An emulsion for one faces may be prepared as follows, this formula being well known: gelatin, one hundred and seventy-five grains; ammonium chlorid, eighteen grains; Rochelle salt, fifty grains; silver nitrate in crystals, seventy-five grains; alcohol, two fiuid drains; water, five ounces. Put thewater, gelatin,ammonium chlorid, and the Rochelle salt into a bottle and when the gel atin is swelled heat to about 100 Fahrenheit, so as to dissolve the gelatin. When the gelatin and the salts are completely dissolved,the crystals of silver nitrate are to be added and the bottle is to be shaken for several minutes. Now maintain the emulsion at a temperature of 100 Fahrenheit for ten minutes, pour out, and allow the emulsion to set. Gut it into pieces and soak or wash in several changes of water. Now drain off the water, melt the gelatinous mass or set emulsion, and add the alcohol, after which coat the cloth with the emulsion. WV hen the coating is dry, a second coating of the same emulsion may be affixed to the back of the cloth, or the back of the cloth may be sensitized by brushing or sponging with the following: ammonium chlorid, three grains; water, one ounce; whipped white of egg, onehalf fluid dram; Rochelle salt, ten grains. When the cloth is again dry, the same side of the cloth (that is, the uncoated side) is sponged or brushed with a solution of silver nitrate, (seventy grains to the ounce of water.) The surface or both surcloth being once more dried is ready for exposure. Any of the many well-known sensitizing preparations may be used, and we may specially mention platinum and gum-bichromate sensitizers. When both surfaces of the cloth are to be coated with the-same emulsion, we may draw the cloth through the liquid emulsion.

Cloth sensitized by the above compound will generally be printed out in the printingframe to the full intensity of image; but a shorter exposure may be given, this shorter exposure being followed by development. A suitable developer is the following: glacial acetic acid, four parts; gallic acid, six parts; sodium acetate, twenty parts; ten-per-cent. solution of lead nitrate, fifteen parts; water, one thousand parts.

hen we intend our sensitive cloth to be used for extremely short exposures followed by development, we sometimes coat both sides of the cloth with an ordinary gelatin-bromid emulsion. If, however, we only wish for a gelatin film on one side, we generally sensitize or coat one surface of the body of the cloth by silver bromid deposited by double decomposition in the substance of the cloth. For example, the cloth is brushed over or saturated with the following: bromid of ammonium, eight grains; whipped white of egg, one-half fluid dram; water, one ounce. hen again dry, the cloth is brushed or sponged with silver nitrate, seventy grains; water, one ounce. The cloth is now washed, after which it is well saturated with ammonium bromid, sixty grains; water, one ounce. The cloth is now well washed in several changes of water, after which it is allowed to dry, and then one side coated with any ordinary gelatin-bromid emulsion. Development and fixing in this case are carried out, as in the case of ordinary photographic work on paper, which has been coated with gelatin-bromid emulsion, excepting that care must be taken to allow a free access of the developing solution to both sides of the material.

Operations with the various sensitive preparations are of course conducted in a subdued or other light known by photographers to be safe and satisfactory in relation to the materials concerned.

WVhen we use cloth which is so thin that a double thickness is not an objection, we sometimes coat one sheet or piece of the cloth with the gelatin emulsion, and we sensitize another sheet or piece of the cloth by brushing, sponging, saturation, or coating, as described. These two sheets may then be superimposed and exposed together, or they may be exposed separately. After fixation the two photographs thus obtained are joined together or cemented together, so as to produce a duplex result similar to that obtained on the single thickness of cloth.

In connection with the fabric hereinbefore referred to it may sometimes happen when the fabric used is not closely woven that the emulsion or sensitizing material penetrates between the threads or percolates through the interstices of the fabric, and at the points of penetration it may-be considered that the two surface films of sensitive material are united and form one thick film. It is obvious that at these points no duplex effect can be produced. Therefore every point where the emulsion penetrates the transparency is less perfect.

Hence it is important that a closely-woven fabric should be used and not a mere skeleton of fine threads.

Referring to the accompanying drawing, (4 represents one sensitive coating; b, the white or light-colored fabric or cloth, and 0 another sensitive coating. Assuming light to be comingin the direction of the arrows, a sharp and dense image results in the substance of the coating 0, the intensity of the various parts of the image being represented for the purpose of illustration by the depth of the shading. Some of the light-rays by passing through the film 0 and penetrating the white or lightcolored fabric or cloth 6 form a second and faint image on the rear coating a. In viewing the duplex picture by looking toward the side on which the tissue was exposed the front image only is seen, this image appearing as an ordinary positive backed up by the white or light-colored fabric or cloth Z). When, however, the duplex picture is viewed as a transparency, both images are seen as they reinforce each other, so that combined they produce the more intense effect which is required for apositive when used as a transparency.

e would have it understood that the boundariesbetween the coatings a and b and the fabric or cloth 0 may not always be so sharply defined as suggested in the accompanying diagram, as they may to a certain extent merge into each other.

\Vhat we claim, and desire to secure by Letters Patent of the United States, is

1. The herein-described method of producing' a duplex photograph which consists in coating white or light-colored linen, cloth or other translucent or semitransparent flexible woven fabric with a sensitized surface on each side thereof, exposing the said sensitized surfaces and obtaining a duplex representation of the image.

2. In the production of aduplex photograph upon white or light-colored linen, cloth or other translucent "or semitransparent flexible Woven fabric, the herein-described method of preparing the said fabric for receiving the duplex representation of the image consisting in applying a sensitized coating to each side of said flexible woven fabric.

3. In the production of a duplex photograph upon White or light-colored linen, cloth or other translucent or semitransparent flexible woven fabric, the herein-described method of preparing the said fabric for receiving the duplex representation of the image consisting in applying a sensitized surface to each side of said flexible woven fabric, said sensitized surfaces being of the same degree of sensitiveness.

4. A photograph consisting of a representation of the image upon each side of a White or light-colored linen, cloth or other translucentor semitransparent flexible Woven fabric adapted to be simultaneously or alternately visible by transmitted and reflected light, the image upon one side of the fabric being darker than the image upon the other side thereof.

5. A duplex photograph consisting of white or light-colored linen, cloth or other translucent or semitransparent flexible woven fabric having a representation of the image upon each side thereof.

In testimony whereof we have hereunto set our hands, in presence of two subscribing witnesses, this 23d day of March, 190

orro FULTON, WILLIAM MOUNTSTEVEN GI LLARD. WVitnesses:

WALTER J. SKER'rnN, T. SELBY VVARDLE.

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