US2266367A - Positive printing in color photography - Google Patents

Description

Patented Dec. 16, 1941 I POSITIVE PRINTING IN COLOR PHOTOGBAPHY Edwin Bower Bessel, Canoga Park, Calif.

No Drawing. Application April 8, 1939, Serial No. 266,781

26 Claims.

This invention relates to the art of color photography, and more particularly to a. newand improved process for producing composite color prints combining light-reflectant and light-transmittant characteristics, thus being equally valuable when-viewed in the ordinary manner, .by

reflected light as a flprlnt or when illuminated I from behind, as a translucency.

The chief characteristic of this composite color print is its marked similarity to the product designated generally in the photographic trade as a paper print in natural color, yet the type of print disclosed herein is definitely paperless, having no dependence whatever on paper as a light reflectant medium.

Thus, a main object of the invention is to provide a print valuable either as a translucency, or viewable by reflected light.

An object is to provide a composite color print which readily lies flat, because each superposed element thereof is of related material, of identical tensional factor, which is therefore unafof composite print making useful in aerial military photography by means of its great speed in manuiacture, together with lightness of weight, and flexibility of the finished print which permits it to be rolled.

Another object is to provide composite color prints which may be attached, in standard photographic manner by means of dry mounting tissue, to a plane surface mounting, retaining the flatness which is essential to lasting value in a color print.

Another object is to provide for advertising usage composite color prints suitable for window displays and viewing. by daylight, which at night may be viewed as a translucency by transmitted light, without the degradation of color value and display of paper grain which would be objectionable in similarly viewing a composite color print which was paper containing.

A still further object is toprovide, tising usage, a composite color print including advertising matter such as a photographic reproduction of a drawing, or lettering, in combi-. nation with a natural color photograph, which,

when viewed from the front, by reflected light, shows only the advertising display but which, when lighted from behind shows by transmitted for adverlight a pictorial display comprising the natural color photograph produced by a build-up of supprposed registering images.

Also another object is to provide for the graphic arts of photoengraving and lithography a composite color print particularly suited for reproduction, by means of its adaptability to copying byeither reflected or transmitted light, but particularly so that it ispossible, at the option of the engraver, to make one or more of his color separation negatives, in copying'the composite color print for reproduction purposes, by transmitted light, as a translucency, and to make one or more of his separation negatives, in varying selective sensitivities or filtrations, by reflected light, thus, for instance, enabling the making of a key-print separation, for printing in the graphic artsin gray, to be made from the composite print as a translucency, thus being less harsh and contrasty than the same composite print copied as a reflected light print. To a skillful engravensuch possibility of variation of contrast oiiers valuable possibilities of color control, particularly in lithography, when as many assill color separations are made from a subject, for as many printings in difierently colored inks.

Still another object is to provide a dual pictured print, useful for-advertising purposes, in which the finished product consists of two separate build-ups; the front build-up, on transparent image-bearing multiple cellulosic films in permanent adhesion and registerbeing separated from the rear build-up by means of semiopaque cellulosic film material so that, when viewed by reflected light, only the front buildup picture is visible, but when illuminated from behind, both'of the pictures, from the front and rear pictorial build-ups, are viewed as a com-,v

- bination picture, permitting the production of vision type of pictures particularly valuable in the field of advertising.

Other objects, advantages and features of the invention-may appear from the following subjoined detail description thereof, and the appended claims (no drawing being necessary to illustrate the'invention, none is furnished).

In accordance with this invention it has been found that new and improved results can be obtained by associating in a print composed of a build-up of transparent image-bearing fllms of only the type of material of which the imagebearing films are composed, omitting all materials oi alien characteristics, such as paper, from the permanently adhesive associated supersition, and substituting therefor an opaque material of the same composition.

Thus,in a build-up print in which the imagebearing films are cellulosic,'the reflecting element, according to this inventiomshould also be cellulosic and opaque.

Similarly, in a build-up print of image-bearing celluloidal films of non-extensible nature, the reflecting element should preferably be another celluloidal opaque film.

However, it is not foreign to this invention to employ for a reflective element, with a celluloidal I or celloidal build-up a cellulosic opaque reflecting material of similar expanding and contracting tendencies in relation to humidity conditions.

In accordance with this invention, however, a paper refiectant surface is never employed, the omission of paper being a paramount feature of the process.

It is well knownin the art that superposing of transparent image-bearing films in color which are so printed as to correctly reproduce in positive form the selective sensitivity recordings of sensations in a set of color separation negativeswill, when viewed by transmitted light, produce a transparency. As an instance, the trade-marked product fchromatone, consisting of collodion films temporarily attached to a paper base, which is removable in the processes of developing, fixing and washing, is capable of being printed, in a photographic manner behind three negatives of a standard color separation series, after which the collodion film positives resulting from exposure behind the three negatives are appropriately colored in yellow, magenta and blue, representing, in the order named, the printings from the blue sensation, the green sensation and the red sensation recording negatives. The three colored positives, so produced, might thus readily be joined together in adhesion to form a transparency, However, the three collodion, colored-up image-bearing films are in themselves without great value because in-- sufllciently rigid to handle, and insufiiciently light refiectant to act as a positive print for viewing by reflected light. it has therefore been customary, and recommended by the manuiacturers of product, to the three collodion films in superposed registry upon white paper, to act as a refiectant element. However, there has been. a great drawback and disadvanto prints so produced, inasmuch. as the composite paper coilodion print has a marked tendency to wrinkle, curl and buckle, clue to the tensional difierences between the buildup of films of coilodion nature and that oi the paper used as light refiectant element.

It is equally well known in the art that cellulosic films, such as the regenerated cellulose manufactured by Du. Font and their patent licensees and universally sold under he tradenarne Cellophane have the capacity of imagebearing by means of chemical toning, such as iron toning for blue, and bichrornate-dye image production in a wide range of colors. Such image-bearing may be designated as of the integral type, inasmuch as the coloration runs entirely through the depth oi the cellulosic film, in contradistinction to the surface image-bearing which may be attained by the affixing of a carbon tissue image to a Cellophane sheet, as a support, in the manner taught by Spencer, in his British patents. In a manner equivalent to the production on Chromatone collodion stripping film, images in three colors may be produced on Cellophane" films as carbon tissue surface images, as chemically toned images or as bichromate-dye images. It is possible to combine, in one cellulosic build-up, image-bearing colored films produced by more than one, or by all of these methods: for the yellow, an acid-dye bichromate image might be produced from the i aeeascv blue sensation negative of a color separation series; for the blue, a chemical iron tone image might be produced from the red sensation negative; for the magenta, printed from the green sensation negative, a surface carbon tissue imagebearing cellulosic film might be utilized, whether one, or multiple types of cellulosic bearing images producedby such methods are used in combina tion, is a matter of taste as far as the photographic worker is concerned, because, whatever the production method used, the factor of regi tration of the images will be found identical, inasmuch as it is common property and knowledge in the trade that Cellophane, stretched while wet and expanded, in a normal manner and with out undue pressure on a non-extensible support, such as water pervious metal, glass, enamel or Bakelite, may be dried, an image caused therein to form, be again immersed, and have the power of retaining identity of image proportion to other images similarly formed in other films of the identical type of manufacture, even if used to hear an image in color of another type, an example being the association in registry of integral" image-bearers with surface image bearing films.

As an improvementover these known methods, I disclose new methods of preparing Cellophane films for color printing, which consist of the following operations, for. example I produce a film sensitive to light, and resulting in blue coloration by the properly timed exposure behind a negative in the following manner: A cyanotype blue solution, containing iron and ammonium citrate, potassium ferricyanide and hydrochloric acid, is placed in a glass dish. Cellophane films, cut to a-desired size, are immersed therein, a number may be placed in a dish, agit tion is diserable. The Cellophane can absorb only a definite fiuid content, sufficient time is allowed in the dish for such maximum absorption to take place, then one individual is taken from the dish, placed on a plane, smooth, non-absorptive surface, such as glass, and the surplus sensitizer removed from the celiulosic film by squeegeeing. The film may be left in adhesion to the glass, until dry, then exposed to light behind a negative, washed in water, a blue print on Cellophane film, suitable for the blue member in'a three color build-up resulting. When, instead or" a chemical blue toner, an acid dye solution is used, the method is the same, except, after soueegeeing to remove surplus dye, the film is subjected to another bath, in a bichromate, following which it is again squeegeed, to remove surplus bichromate, and dried in the dark. It has been found desirable to immerse the glass plate with the adherent dyed, squeegeed film, directly in the bichromate solution, which may, alternately, be applied manually, or by vaporization. Obviously, such treatment may be accorded to the dyed film, whether completely dried, or damp from the first process of dye im- 'pregnation.

tive from which it was exposed to light, allowing' a few minutes for dye absorption. Simple acidified washing removes the surplus dye from parts not affected by the photographic exposure to light, an excellent image-bearing Cellophane film, of great contrast, resulting. Instead of immersional applications of either the bichromate solution, the dye solution, or both, manual or mechanical application may be substituted.

In the known photographic art, to convert .a build-up of image-bearing sheets of whatever nature as to composition, but transparent, into a light refiectant print, viewable as an ordinary painted or printed picture might be viewed, it has been necessary to use a paper base of some kind, and to build up, on this paper base, and in adhesion, the constituent color-images, in the material selected, to form a natural color picture. This building up process is used in "carbro or carbon tissue prints built up directly upon a sheet of paper with extremely thin, unsupported carbon tissue films; by Cello-' phane supported carbon tissue images, by-dye or toned Cellophane image-bearing films; by collodion films of the Chromatone" or "Kodalith stripping film type. It is to be noted that the extremely thin, non-tensional carbon-tissue images of the "carbro type offer no special trouble in wrinkling or curling after the print has been manufactured, but that all types of collodion films, Cellophane films or celluloidal.

films, bearing images, possess such radically different factors of stress and tension from the 3 maybe readily mounted with such dry-mounting tissue methods: such printaoi type known in the art, include Carbro prints and Eastman wash-off prints," which are relatively thin. On the other hand, it has been almost impossible to satisfactorily mount on cardboard or other .plane surface, by means of dry-mounting tis-v paper, with its perpetual tendency to curl. Such heavy prints have in general necessitated double mounting, or taping upon heavy, board-like material for permanent support, adding to exhibition, mailing and framing difficulties. However, in the case of flexible build-up prints of cellulosic films, I have discoveredthe. marked advantage of being able to use dry mounting tissue methods in a manner similar to prints paper on which they are mounted for light re- 1 fiectant purposes, while wet and in process of ages, that, in drying, tendencies to wrinkle, curl, buckle, blister and crack are almost certain to be noticeable, even in such instances as when cellulosic sheets are caused to adhere to the back of the paper light-refiectant member of the build-up, in an effort to neutralize the tension caused by the image-bearing material on the front of the paper sheet. Changes of weather and humidity, over a period of time, often result, by means of such wrinkling, in destruction of the exhibition value of such prints, and this tendency, known in the art, has always proved detrimental to the commercial usage of such paper-combining prints, in which the adhesive association with transparent cellulosic, colloidal or celluloidal films has so generally resultedin wrinkling and curling troubles.

A marked disadvantage and detriment to cellulosic prints of the build-up type, combining image bearing Cellophane films in supersit on on paper with other Cellophane" films on the back of said paper as a means to minimize curling tendencies, has been the thickness and bulk of the resulting print, ofiering serious difiiculties in mounting. In the photographic business of supplying prints for use in commerce, that is,-in the commercial advertising usages, as well as portraits, the most acceptable method for mounting a print, and that in general usage in preparing prints for exhibition, has been with materials such as the "dry mounting tissue? sold under that trade name by the Eastman Kodak Company of Rochester, New York. By this means, a print may be afllxed to a papercardboard plane surface mounting, by means of heat application which so melts the dry-mounting tissue that it becomes permanently adheof carbro or wash off, type. Unlike the paper containing prints, in. which the paper and the cellulosic films haveatendency to separate if the print is cut into the paper portion,

in trimming, the all-cellulosic build up may-be trimmed, after completion, to any desired size on a photographic trimming cutter, and then' dry-mounted.

Oneof the most important commercial markets possible for natural color photography-is in window display use; heretofore thedifilculty and expense of manufacturing color prints has made the cost for such usage almost prohibitive. By my methods herein disclosed, it will be possible to produce color prints at much less cost and trouble than heretofore, due to the simplicity of the process and the obviation ofloss which has always occurred heretofore in print making owing to the percentage of prints made which become valueless due "to wrinkles, buckling, blisters and kindred evils caused by the adhesive association of paper and the unrelated, differing tension factor materials comprising and superimposed build-up of image-bearing. transparent films.

When, according to this method, the light re- .fiectant quality in the composite built-up color tained by lighting the printfrom behind, and.

thus viewed by transmitted light, as a trans-, lucency, the same print that proved beautiful and effective as a daylight display becomes even more attention-arresting at night. For theatrical and motion picture display frames the commercial value of such a print is obvious.

Another great drawback, known in the art in I connection with the process of building up transparent films to form composite color picture on a light refiectant paper base has been overcome by my novel method of production. Paper by its very nature has the tendency to absorb and 1 hold water to much greater degree than cellulosic film of the Cellophane" type.

Because of this water absorbing and holding nature of paper, particularly in the water its removal from the glass support, in wet,

weather, a reverse action. takes place, and. oftenwhen a composite color print is seemingly dry and removed from its giass'manufacturing support, the paper light reflectant element therein is actually still'damp, with the result that it soon begins to curl and wrinkle.

Experiments with 'the .type of all-cellulosic print herein disclosed have proved conclusively that the composite thus formed dries very quickly and evenly, thatconsiderable heat and forced air may be used in drying, without detriment to the print, thus making possible and practical the removal of the finished composite color print.

from its manufacturing support in as little as thirty minutes after completion of the build-up, definitely overcoming a most hazardous and uncertain factor always present in the making of paper containing build-up prints. Such speed of completion is an added value'in the delivery of finished work, and in military aerial usage fills the requirements much more fully than any type of print requiring a considerable period of time to dry. The flexibility of these composite prints permits military usages impossible in a completely rigid, paper containing build-up prin In a preferred form of this invention, a rigid support is chosen which in size is larger than the print to be made. As an illustration, the making of an 11 by 14 inch print will be described.

The rigid, non-extensible support may be of glass, Bakelite, metal or Celluloid. It need not be transparent, but must not be water pervious.

I For the making of an 11 by 14 inch print it should be 12 by 15 inches in size.

Regenerated cellulose of white opaque characteristics, such as Du Pont Cellophane #300 plain opaque is cut to 14 by 18 inch size, thus being marginally larger than the rigid support. A sheet of this opaque material is placed for a few moments in a pan of water, then placed over the rigid support, so that the overlapping margins drop down, it being advisable that the rigid support be elevated above the working table, for instance, on an eight inch block of wood. The overlapping edges are made to adhere to the back of the support by a convenient adhesive, after the surplus water on the surface of the cellulosic material in contact with the support is removed by pressure, preferably by a windowwashing type of squeegee. Note that only the overlapping edges are caused to adhere to support, and only to the back of the support. Another sheet of the same opaque cellulosic material is now put into the pan of water, the operation is repeated; only the back of, the support is brought into adhesion with the overlapping marginal material of opaque Cellophane. The third sheet ofidentical material is put in the panof water: this time the entire surface of the second sheet of opaque material is lightly but evenly covered with the adhesive material, which may be a solution of transparent, waterwhite gelatine. The marginal, overlapping edges are turned under, and caused to adhere to the back of the support. If it is desired that the finished print shall be fairly heavy, and used 'mainly for viewing with reflected light, a fourth sheet of opaque cellulosic material is added in a manner identical to the operations governing the third sheet set'down.

It should be noted that no adhesive is placed between the first and second sheet put down, the object being to protect the print from any possibility of seepage of adhesive material that might reach the surface of-the rigid support,

making it diiilcult to later remove, without tearing the cellulosic under surface, from the rigid support. After removal of the finished print, in a manner which will be described, this first sheet 'put down is peeledoif and thrown away. Howused. If two sheets of opaque material corre- I picture.

spending in weight to standard #600 transparent Cellophane were used, they should, in adhesion, provide adequate opaquity for light reflection, though another might optionally be added, if fi rther stiflening of the finished print was desira le.

The opaquecellulosic backing is now ready for the superposing in register of transparent image bearing films comprising the composite color By whatever method the image-bearing sheets are produced, the next step is to select one of the component colorations, ailix perma- 'nently by means of adhesive the transparent material bearing it, on top of the final opaque sheet adhering in supersition to at least one other opaque sheet marginally adhering to the back of the rigid support, see that this image-bearing sheet is properly in adhesion, without air bubbles, and then, on top of -it, in whatever sequential order of colorations is deemed advisible affix in register and adhesion the remaining imagebearing transparent sheets needed to complete a natural color still picture. The composite picture may now be dried by means of an electric fan, in a few minutes.

After the drying operation is complete, a sharp knife edge is used to cut through all the superposed layers of material on the front of the rigid support, comprising both the transparent imagebearing sheets and the opaque reflectant sheets, right through to the support. This cutting should be outside the pictorial area of the imagebearing sheets, in the margins on the front of the support. After this cutting, the composite, complete print readily peels off from the support, and can then be trimmed to desired size and proportion and mounted, at once, with dry mounting tissue, or put between rigid, smooth plane surfaces for future usage. Such prints may obviously be used unmounted.

The image-bearing transparent sheets may be considerably smaller than the size, of the rigid support. If a matte surface is desired, the entire composite print may be covered with a cellulosic, matte surface transparent material such as marketed under the trade name of Transolene," or a product of similar nature, such as a matte surfaced water absorbent cellulosic sheet manusource isprovided behind the composite picture tone collodion stripping paper: in each case, after printing development and fixation, the

silver image is colored byknown methods of toning or dyeing, and then assembled in -regis-,

the lettering and picture are both visible.

The same principle may be utilized by laying down, over a single opaque sheet on the rigid support, the series of transparent image-bearing sheets in registered superposed adhesion necessary to complete a natural color picture. For

, instance, this might be the pictureof a lovely tered adhesion on the opaque cellulosic material comprising the refiectant backing of this invention. Carbon tissue prints on thin transparent supports, cellulosic or celluloidic, are also suitable for employment in association with the type of opaque backing disclosed herein.

We have sometimes found it more convenient, in practice, instead of overlapping the white opaque Cellophane films comprising the light reflectant-light translucent backing, over the rigid support, as heretofore described, to use a larger sheet of glass than 12 by 15 inches, as previously suggested for an 11 by '14 inch print. Take, for example, a piece of glass 15 by inches in size; cut the opaque white Cellophane sheet to 14 by 18 inches Then, instead of the marginal overlapping previously suggested, put

the wet sheet on the glass, squeegee out the surplus water, with a brush place the adhesive only on the outer edge of the Cellophane. Upon this sheet, in supersition, additional sheets of the white opaque cellulose material are added, these sheets beingmade adhesive to each other. and the first sheet by all over adhesive applications. When the required number of sheets are in place for the opaque or translucent backing, the image bearing sheets are put down .in succession; first, for instance, the yellow positive image bearing Cellophane, second, the magenta positive image bearing Cellophane in exact registry, then the blue image bearing Cellophane film, and if a four color print is desired, a black image transparent film is added, all in registry and in permanent adhesive relationship to the opaque backing films. All these operations are carried out, as to registration, while the image-bearing films are wet; when the build-up is complete, the composite color photograph should be quickly dried and removed from the temporary support by cutting with a sharp knife between the pictorial edge of the picture and the margin of the lower Cellophane sheet attached to theouter edge of the rigid support.

In the manufacture of window display color pictures by this method, in which the requirement is viewability by either transmitted or reflected light, the number of opaque sheets behind the image-bearing sheets is kept at a minimum.

The method of manufacturing a color picture which is not at all visible by reflected light, but which may be viewed as a translucency when a light source is provided behind it, may be as follows: The opaque backing is made in the usual manner; the image bearing sheets are superposed in registered adhesion, further opaque sheets, or a single opaque sheet, is caused to adhere over the composite color picture. On this sheeting of opaque material, for advertising pur-' poses, a lettering may be printed in known manner.- The underlying pictorial composition is not now apparent to a casual glance, but such lettering -as is provided on the surface of the final opaque sheet is readable. When a light house, with children playing in the yard. Then an opaque sheet, or multiple opaque sheets, are arranged in adhesive supersition over this complete picture; With image-bearing transparent sheets of another subject (which for 11- lustration might be a young couple seated on a hilltop, with a clear sky above them), further build-up of superposed ,registering adhesive sheets completes another color picture, visible,

of course, by reflected light, while the rear picture remains invisible behind the opaque sheet. When transmitted light source is provided behind the picture as a whole, the lovely house, with children playing in the yard, is shown as the young couples vision, in the sky. Such combinations of dual ideas are obviously valuable from an advertising standpoint.

Speed of completion of any type of color print is a most important factor in determining its commercial value. It should be noted that the ordinary build-up print consisting of several colored image-bearing films, mounted on top of a light reflectant paper sheet, is turned back by other multiple adhesively attached cellulosic films in the usual effort to minimize stress or tension and thus reduce the curling characteristics of such a composite print, requires after the completion of the image-bearing film build-up a period of from six to twenty-four hours, depending on humidity and temperature conditions, before it is sufliciently dry to be removed from its temporary rigid support.

I have demonstrated that a print produced by my new and unique method of assembling multiple, transparent image-bearing films in permanent adhesion with each other and multiple imageless white opaque cellulosic films results in a composite color picture. which may be dried very quickly and removed from its temporary rigid support. No detrimental effect on. the composite color print is caused by the use of warm,

forced air, and by the combination of heated air.

and an electric 'fan'we have discovered that it is possible to remove such a print from its support, fully dried and ready for any commercial usage, including dry mounting, in as short a time as twenty minutes after the image-bearing sup'erposing build-up operation is complete. In time of war, the quick completion of military color prints would be of extraordinary value to the. aerial forces of our nation, the ability to assemble such image-bearing color films in a flying laboratory," and drying them speedily by readily available air pressure being a feature of obvious importance.

Within the proper scope of this invention are several other variations of composite color print making, in which all the factors of stress and tension are equalized by employing similar material for each associate permanently adhesive film in a composite build-up.

For instance, commercial usage can be found occasionally for such a composite build-up which is entirely of light transmittant and not light reflective characteristics, but which is sufficiently rigid for handling, trimming with a cutter and standing upright in the manner of an ordinary photographic print, let us say on a mantlepiece resting against a wall; Such a print is produced, by my method, by the mere substitution of multiple transparent cellulosic sheets on the backing, instead of multiple semi-opaque sheets. I have discovered that a rigid transparency, so

produced, may be readily converted into a light-- refiectant print either by adding another or multiple sheets of semi-opaque film at any later time, by adhesion, or by spraying on the back thereof an even coating of white opaque cellulosic material in solution, or other white opaque material that may be readily applied with an air brush. Kodachrome transparencies, in themselves consisting of multiple emulsions differentially colored to produce a composite color photograph adherent to a celluloidal base, may be rendered light-reflectant and utilized as translucencles when adhesively mounted upon a base of semi-opaque cellulosic material or when treated, with a spray, on the back celluloidal side, to obtain a light refiectant effect. Similar treatment may convert either Dufaycolor transparencies or Agfacolor transparencies into translucent light reflecting prints. It is obvious tha' such conversion to translucency increases the value of such. transparencies, the combination of multiple color registered images in any form to complete a composite color photograph with a paperless, light-refiectant yet translucent support being fully within the scope of this invention, whether such a translucent support be used as a base before or after the coloration of the images or as separate from, or as integral with such images in the process of coloration or processing.

Having thus described the invention, what I claim as new and novel and desire to secure by Letters Patent oi the United States is:

l. in the art of color photography, the method of producing a composite color photograph which comprises providing in appropriate coloration multiple transparent image-bearing films representing in positive form the selective sensitivities recorded in a set of color separation negatives; providing a rigid substantially plane surfaced non-pervious support and mounting thereon While wet and expanded a plurality of sheets of white opaque regenerated cellulose material of size larger than said rigid support with marginal portions of said opaque material overlapping margins of said rigid support and being adhesively secured to each other and to the reverse oi said support; mounting in permanent adhe-' sion on the outer sheet of said white opaque material one of the said thin transparent imagebearing films in superposed adhesional relationship, mounting successively in image registry the remaining said transparent image-bearing films to complete a natural color representation, each film being in permanent adhesion to its neighbor and to the opaque films comprising the refiectant base; after drying removing the composite photograph thus produced by peeling from its rigid temporary support.

2. the art of color photography, a process for producing a positive transluceny comprising multiple adhering Cellophane films which includes the following steps; providing a rigid substantially plane polished. surface non-pervious support and covering therewith a single film of Cellophane in a condition of Wet expansion, said film bein of a size larger than the rigid support,- the marginal portions of said Cellophane film overlapping margins of said rigid support and being adheslvely secured only to the reverse side of said rigid support by a solution containing gelatine, surface moisture being removed from the face of the filth on the front of the rigid support by squeegeeing, followed by drying of this first or protectional film; the operation is identically repeated with a second Cellophane film of plain white opaque type; adhesive similarly being placed only on the overlapping marginal portions of the film, causing it to adhere only to the back of the rigid support, the squeegee being again used to eliminate surplus moisture and air bubbles: drying follows; a third sheet of Cellophane of plain white opaque quality is prepared in similar size being placed in water to obtain maximum expansion; gelatin adhesive is applied to the entire surface of the second film on the rigid support; the third is placed in contact, squeegeed, thus being caused to adhere; the marginal overlapping portion of said third film is then adhesively secured to the back of the rigid support; the operation as described for the third film is exactly repeated with a fourth Cellophane film of plain white opaque type; simultaneously with the foregoing operations a film of plain white opaque Cellophane is impregnated with a solution containing potassium ferricyanide, hydrochloric acid, iron and ammonium citrate; the impregnated sheet is dried in darkness while stretched on another rigid support; exposure of the impregnated white opaque film to light behind the red sensation recording negative member of a set of color separation negatives; production of an lron blue image results; the 'surplus toning chemical is washed oif in plain water; impregnation follows with a solution containing a bichromate, with the dual result of fixing the blue coloration andr'endering the film again sensitive to light; the film is again dried in the dark on a rigid support; the film is next exposed to light behind the green sensation r'ecording member of the set of color separation negatives in proper registry with the iron blue image already formed in thc Cellophane film, after printing, the film is impregnated with a solution containing an acid magenta dye, which mordants into the bichromate image formed by the printing operation behind the green sensation recording negative; the plain white opaque Cellophane film, hearing magenta and blue images, is now washed in a strong acid solution, setting both colors; simultaneously with these operations another Cellophane film impregnated with a bich'rornate and dyed in the clerk is exposed to light behind the blue sensation recording member of the set of color separation negatives; after exposure impregnation follows with a yellow acid dye; immersion in a strong acid solution follows setting the yellow dye in the regions of the film in which bi'chromate image has been formed by light exposure behind the negative and releasing unwanted yellow dye from the non-bichromated area of the film; the Cellophane film bearing the blue plus magenta image is now permanently attached by adhesion to the build-up of imageless film on the rigid support; the yellow image-bearing Cellophane film is registered to the blue-magenta image-bearing film and allowed to remain in contact suificient time to discharge its dye content into the blue-magenta image, thus forming a three color image on a single film of plain opaque Cellophane; the yellow image bearing film is now discarded; the entire Cellophane build-up is dried by the application of heat and air; with a sharp knife the films comprising the structure is discarded after the translucency formed by the foregoing operations is peeled off the rigid support.

film printed behind the blue sensation negative I with yellow colorizer; bichromate images formed by printing in each instance acting as a mordant 3. A process in color photography including the preparatory supersltion of four imageless Cellophane films on a rigid support, as described in claim 2; a fifth film of plain white opaque Cellophane is impregnated with a solution containing a bichromate. stretched on a rigid support and dyed in the dark; the film is then exposed to light behind the green color sensation recording member of ,a' set of color separation negatives and printed to form a bichromate image; impregnation follows with an acid magenta dye in aqueous solution; the fihn is then treated with a strong acid solution to set the dye by mordanting in the-bichromate image; washing follows to remove dye from the unexposed areas; the film is then mounted with adhesive to the superposed structure of -four imageless films on the rigid support; squeegeeing follows to eliminate surplus moisture and obtain smoothness; simultaneously with the foregoing operations a sixth Cellophane film has been similarly bichromated, dried, exposed behind a blue sensation'recording negative, impregnated with a yellow acid dye, fixed with acid solution, washed, and while wet' and expanded caused to adhere in image registry with the magenta image hearing film on the Cellophane film build-up; simultaneously from the red sensation recording member of the set of color separation negatives a positive relief film with gelatine surface has been prepared and impregnated with an acid blue imbibition dye, brought into image registry with the yellow image bearing film of the buildup, the blue dye imbibing thereto, forming an all-Cellophane three color translucency when dried and removed from the temporary rigid support.

4. A process in color photography including the following steps: mixing a solution containing water 90% potassium bichromate 10%, designated as the sensitizer solution; mixing a solution containing water 95%, an acid magenta dye 5%, designated as the magenta colorizer; mixing a solution containing water.90%', an acid yellow dye designated as the yellow colorizer; mixing a blue sensitizer-colorizer solution, containing iron and ammonium citrate, potassium ferricyanide and hydrochloric acid; preparing multiple films of plain white opaque and plain transparent Cellophane by cutting to the proper size; stretohing these while wet and expanded, as single films, over rigid supports, and drying; preparing multiple superposed sheets of plain white opaque Cellophane in adhesion on a temporary rigid support; providing a set of color separation negatives recording negative part-pictures in green, blue and red sensation selective sensitivities, proper .for printing in magenta, yellow and blue, respectively; impregnating a Cellophane film with the sensitizer solution and drying in darkness; exposing the dried, sensitized film to light behind the green sensation recording member of the color separation negative set; similarly impregnating with sensitizing solution another Cellophane film, drying and subsequently exposing to light behind the blue sensation recording member of the color separation negative series; impregnating the two films thus printed with colorizers, the film printed behind the green sensation negative with magenta colorizer; the

for the acid dye content of the colorizers; simultaneously impregnating a third Cellophane film with blue sensitizer colorizer, drying the film in the dark and exposing to light behind the red. sensation recording member of the color separation negative series; all three films bearing colors are immersed in acid baths to fix the respective colors; washing follows to clear the highlights; the three films are successively caused to adhere to the build-up of multiple imageless Cellophane films of plain white opaque quality, in image registry and permanent adhesion, to form a natural color translucency.

5. A process in color photography which includes the following steps; impregnating a Cellophane film with a solution containing iron and ammonium citrate, hydrochloric acid and potassium ferricyanide; stretching over a rigid support; drying in darkness; exposing to light behind a red sensation recording negative to form a blue image; immersing in a solution containing a bichromate to fix the blue image and further sensitize the film to the action of light; exposingto light behind a blue green sensation recording negative; forming by such exposure a bichromate image capable of mordanting acid dyes; impregnating the film with a solution containing a red acid dye; immersing in an acid solution thus fixing both blue and red images and eliminating red dye from the area in which there is no mordanting image caused by light exposure; washing the film to further clear the highlights, thus producing a blue and red image from two separate negatives by light exposure on a single Cellophane film.

6. In the art of color photography, the method of producing a composite color photograph which comprises providing in appropriate coloration a single plain white opaque image-bearing film representing in positive form one color aspect of the selective sensitivities recorded in a set of color separation negatives; providing in appro- 'priate coloration multiple transparent imagebearing films representing in positive form other color aspects of the selective sensitivities recorded in said set of color separation negatives; providing a rigid substantially plane surfaced nonpervious support and mounting thereon while wet and expanded a plurality of sheets of white opaque regenerated cellulose material of size larger than said rigid support with marginal portions of said opaque material overlapping margins of said support; adhesively securing said films to duced by peeling from said rigid temporary supa set of color separation negatives; providing at least one more transparent image bearing film in appropriate coloration representing in positive form the remaining selective sensitivities recorded in said set of color separation negatives; providing a rigid substantiall plane surfaced nonpervious support and mounting thereon while wet and expanded a, plurality of sheets of white opaque regenerated cellulose material of size larger than said rigid support with marginal portions of said opaque material overlapping margins of said support and being adhesively secured to each other and to the reverse of said support; mounting in permanent adhesion on the outer sheet of said support consisting of said plain white opaque material the said image-bearing plain white opaque film in superposed adhesional relationship; mounting successively in image registry the said transparent image bearing films to complete a natural color representation, each film being in permanent adhesion to its neigh hot and to the opaque films comprising the refiectant base; after drying removing the composite photograph thus produced by peeling from its rigid temporary support.

8. In the art 01 color photography, the method of producing a composite color photograph which comprises providing in appropriate coloration a single transparent image-bearing film representing in positive form the selective sensitivities recorded in the exposing of blue sensation, green sensation and red sensation light sensitive photographic material in a single simultaneous exposure in the photographing of an object; providing a rigid substantially plane surfaced non-pervious support and mounting thereon while wet and expanded a plurality of sheets of plain white opaque regenerated cellulose material of size larger than said rigid support with marginal portion of said opaque material overlapping margins of said support and being adhesively secured to each other and to the reverse of said support; mounting in permanent adhesion on the outer sheet of said opaque material the said thin transparent multiple image bearing film in superposed adh'esional relationship to complete a natural color representation, said film being in permanent adhesion to its neighbor, the outer sheet of the opaque films comprising the refiectant base and to all the other films comprising said reflectant base; after drying removing the composite photograph thus produced by peeling from its rigid temporary support.

9. In the art of color photography, the method of producing a composite color photograph which comprises providing in appropriate coloration multiple image-bearing films representing in positive form the selective sensitivities recorded in a set of color separation negatives; providing a non-image-bearing film with matte surface of regenerated cellulosic transparent material; providing a rigid substantially plane surfaced nonpervious support and mounting thereon while wet and expanded a plurality of sheets of white opaque regenerated cellulose material of size larger than said rigid support with marginal portions of said opaque material overlapping margins of said rigid support and being adhesively secured to each other and to the reverse of said sup-- port; mounting in permanent adhesion on the outer film of said white opaque material one of the said thin image-bearing films in superposed adhesional relationship; mounting successively in image registry the remaining said imagebearing films to complete a natural color representation; mounting in superposed adhesional relationship said matte surface film; each film being in permanent adhesion to its neighbor and to the opaque films comprising the reflectant base; after drying removing the composite matte-surface photograph thus produced by peeling from its temporary rigid support.

10. In the art of color photography, the method of producing a multiple subject composite color photograph which comprises providing in appropriate coloration multiple transparent imagebearlng films representing in positive form the color aspects of multiple selective sensitivities recorded in a set of color separation negatives; providing in appropriate coloration at least one additional image-bearing film representing another subject, drawing or lettering; providing a iigid substantially plane surfaced nonpervious support and mounting thereon while wet and expanded a plurality of sheets of white opaque regenerated cellulose material of size larger than said rigid support with marginal portions of said opaque material overlapping margins of said rigid support and being adhesively secured to each other and to the reverse of said support; mounting in permanent adhesion on the outer sheet of said white opaque material one of the thin transparent image bearing films in superposed adhesional relationship; mounting successively in image registry the remaining said trans- ;parent image-bearing films to complete a natural color representation of one of the subjects; mounting in superposed adhesional relationship the said transparent image bearing films representing the other subject, drawings or letterings, to complete a multiple subject composite color representation; each film being in permanent adheslon to its neighbor and to the opaque films comprising the reflectant base; after drying removing the composite photograph thus produced by peeling from its rigid temporary support.

11. In the art of color photography, the method of producing a composite color photograph which comprises providing in appropriate coloration multiple transparent image-bearing films representing in positive form the selective sensitivities recorded in a set of color separation negatives; providing a permanent,'substantially plane surfaced support consisting of paper-cardboard; providing dry mounting tissue and heat apparatus necessary for adhesional dry-mounting operation; providing a temporary rigid substantially plane surfaced non-pervious support and mounting thereon while wet and expanded a plurality of sheets of white opaque regenerated cellulose material of size larger than said rigid support, the marginal portions of said material overlapping said rigid support; and being adhesively secured to each other and to the reverse of said rigid support, mounting in permanent adhesion on the outer sheet of said white opaque material one of the said thin transparent imagebearing films in superposed adhesional relationship, mounting successively in image registry the remaining said transparent image-bearing films, each film being in permanent adhesion to its neighbor and to the opaque films comprising the reflectant base; removing the composite thus produced by peeling from its rigid temporary support; arranging said composite in superposed relationship to said permanent support with dry mounting tissue sandwiched between; applying heat to effect adhesion by means of the dry mounting tissue thus completing a natural color etaoaaer opaque regenerated cellulose material of size composite photograph suiilciently rigid for commercial usage. a

' 12. In the art of color photography, the method of providing a dual pictured composite color photography viewable by reflected light as a single-subject picture and by transmitted light as a double subject picture which comprises providing in appropriate coloration multiple transparent image-bearing films representing in positive form the selective sensitivities recorded in a set of color separation negatives, these comprising the first subject; providing in appropriate coloration multiple transparent image-bearing films representing the color aspects of the second subject, providing multiple films of plain white opaque regenerated cellulose: in condition-o! wet expansion; providing a rigid substantially plane surfaced non-pervious support and mounting thereon while wet and expanded a' plurality of films of plain white opaque regenerated'cellulose material of size larger than said rigid support with marginal portions of said opaque material overlapping margins of said rigid supportfand being adhesively secured to each other and tofthe reverse of said support; mounting in permanent adhesion to the outer film of said plain white opaque regenerated cellulose material one of the thin transparent image bearing films Ofthesecnd subject in superposed adhesional relationship; mounting successively in image registry. the remaining said transparent image-beari'ngfilms of the second subject, to complete fullj pictorial representation of said second subject; mounting in superposed adhesional relationship, on'top of said second composite subject multiple films of .white plain opaque regenerated cellulose sufficient to obscure viewing of said second subject when viewed by reflected light; mounting in permanent adhesion on the outer sheet of said white opaque material one of the said thintra'nsparent films comprising one color aspect of the first subject in superposed relationship; mounting successively in image registry the remaining larger than said rigid support with marginal portions of said opaque material overlapping margins of said rigid support and being adhesively secured to each other and to the reverse .of said rigid support; mounting in permanent adhesion on the outer film of said plain white opaque material one of the said image-bearing "sheets in superposed adhesional relationship;

mounting successively in appropriate registry the remaining said transparent image-bearing [films to complete the representation; each film being in permanent adhesion to its neighbor and 'to. the opaque films comprising the refiectant base; after drying removing the composite photo- .graphthus formed by peeling from its rigid temporary support.

.14. In the art of color photography, the method of producing a matte surface composite color photograph which comprises providing a composite color photograph adherent to a celluloidal base consisting of multiple emulsions diiIeren-- tially colored to represent in positive form the selectivelsensitivities recorded by adherent sufaced non-pervious supportand mounting there- .on while wet and expanded a plurality of films said transparent image-bearing films comprising the first subject, thus completing a naturalcolor representation of the first subject viewable by reflected light, each of the films comprising the pictorial'representations of the'first subject and of the second subject being in permanent adhesion to its neighbor and to the opaque films comprising the original opaque base on the temporary rigid support and the structureoi' said plain white opaque material between the second and the first subjects; after drying removing the double subject composite photograph thus produced by peeling from its rigid support, thus manufacturing a product in which only the first subject, mounted on top of the dividing plain white opaque material is visible when viewed by reflected light but that when-viewed by transmitted light shows both the first and second subjects superposed as a double composite photograph.

13. In the art of color photography, the method of producing a composite color photograph including multiple subjects which comprises providing in appropriate coloration-multipletransparent image bearing films. representin .difiering color aspects of appropriately combinable subjects, designs, letterings and drawings as recorded in photographic negatives proper for the rendition thereof 1 in multiple colorations; providing a rigid substantially plane surfaced =-nonpervious support and mounting thereon while wet and expanded a plurality of'films of plain white of plain white opaque Cellophane oi size'larger than said rigid support with marginal portions oi saidwhite opaque Cellophane overlapping margins of said support and being adhesively secured to each other and to the reverse of said support; mounting in permanent adhesion on the outer sheet of said opaque Cellophane material the said thin transparent celluloidal base film; mounting in further superposed adhesion .the said matte surface Cellophane film; each of said films being in permanent adhesion to each other and the build-up of plain white opaque Cellophane films; fafter drying removing the matte surface natural color photograph thus support. a

15. In the art of color photography, the method of producing acomposite color photograph which comprises providing in appropriate coloration a single transparent image-bearing film representing in positive form the selective sensitivities recorded in the exposing of blue sensation, green sensation and red sensation light sensitive superposed homogenous emulsions in the photographing of an object; providing a ,non-image-bearing film with matte surface of regenerated transparent cellulosic material; providing a rigid substantially plane surfaced nonpervious support and mounting thereon while wet and expanded a plurality of sheets of plain :white opaque regenerated cellulose material of size larger than said rigid support with marginal portion of said white opaque material overlapping margins of said support and being adhesively secured to each other and to the reverse of said support; mounting in permanent mounting thereon while wet and expanded a pinrality of films of plain white opaque regenerated cellulose material of size larger than said rigid support with marginal portions of said opaque material overlapping margins of said rigid support and being adhesively secured to each other and to the reverse of the said support; mounting in permanent adhesion on the outer sheet of said white opaque material one of said imagebearing films in superposed adhesional relationship; m'ounting successively in image registry the remainingsaid image-bearing films to complete a natural color representation; mounting in superposed adhesional relationship a matte surface non-i'mage-bearing film, each film being I in permanent adhesion to its neighbor and to the opaque films comprising the reflectan'tbase, after drying removing the composite photograph thus produced by peeling from its rigid tempo- 'y support.

17. In the art of color photography, the methd of producing a composite color photograph which comprises providing in appropriate coloration multiple collodion image bearing films representing in positive form the selective sensitivities recorded in a set of color separation negatives; providing a matte surface imageless transparent film; providing a rigid, substantially plane-surfaced non-pervious support and mounting thereon while wet and expanded a plurality of sheets of white opaque regenerated cellulose material of size larger than said rigid support with marginal portions of said opaque material overlapping margins of said rigid support and being adhesively secured to each other and to the reverse of the said support; mounting in per- -manent adhesion on the outer sheet of said opaque material one of said image-bearing collodion films in superposed relationship; mounting successively in image registry the remaining said collodion image-bearing films to complete a natural color representation; mounting in superposed relationship said matte surface fllm; each film being in permanent adhesion to its neighbor and to the opaque films comprising the refiectant.

base, after drying removing the composite photograph thus produced by peeling from its temporary rigid support.

18. In the art of color photography, the method of producing a composite color photograph which comprises providing in appropriate coloration at least one image-bearing film representing in positive form the selective sensitivities recorded in exposing multiple differently selective photographic emulsions to an object; providing a matte surface imageless transparent film; providing a rigid, substantially plane surfaced nonpervious support and mounting thereon while wet and expanded a plurality of sheets of white opaque regenerated cellulose material of size larger than said rigid support with marginal portions of said opaque material overlapping marsecured to each other and to the reverse of the said support; mounting in permanent adhesion on the outer sheet of said opaqu material said image-bearing material providing image registry of component selective sensitivity recordings of the object photographed; mounting in superposed adhesional relationship said matte surface film, each film being in permanent adhesion to its neighbor and to the opaque films comprising the refiectant base; after drying removing the composite photograph thus produced by peeling from its temporary rigid support; attaching in permanent adhesion to a paper-cardboard permanent support by dry mounting tissue in the presence of heat.

19. In the art of color photography, the method oi producing a composite color photograph which comprises providing in appropriate coloration multiple image-bearing films representing in positive form the selective sensitivities recorded in at least one set of color separation negatives; providing a matte surface transparent film, providing multiple plain white translucent films; providing a rigid substantially plane-surfaced non-pervious support and mounting thereon while wet and expanded a plurality of sheets of said white translucent material oi size larger than said rigid support with marginal portions of said translucent material overlapping marginal portions of said rigid support and being adhesively secured to each other and to the reverse of said support; mounting on the outer sheet of said white translucent material one of said image-bearing films in superposed adhesional relationship; mounting successively in appropriate registry the remaining image-bearing films of one color separation series; mounting other remaining image-bearing films in appropriate registry; mounting said matte surface film in superposed adhesive relationship; each film being in permanent adhesion to its neighbor and the opaque build-up of individually translucent films comprising the reflective base; after drying, removing the composite photograph thus formed 45 by peeling from its rigid temporary support.

20. In the art of color photography, the method of producing a composite color photograph which comprises providing in appropriate colorotion multiple image-bearing films at least one of which is of surface-image carbon tissue bearing type, said films representing in positive form the differing selective sensitivities recorded in at least one set of color separation negatives; providing multipl plain white translucent-toopaque Cellophane films; providing a rigid substantially plane surfaced non-pervious support and mounting thereon while wet and expanded a plurality of sheets of said plain White Cellophane material; said material being of a size larger than said rigid support with marginal portions overlapping said rigid support and being adhesively secured to each other and to the reverse of the said support; mountin on the outer sheet of said white Cellophane material one of said image-bearing films in superposed adhesional relationship; mounting successively in appropriate registry the remaining image-bearing films, each film being in permanent adhesion to its neighbor and to the opaque build-up of films comprising the refiectant base; after drying removing the composite photograph thus produced by peeling from its rigid temporary support.

EDWIN BOWER HESSER.