US1789615A - Photographic line print and method of making the same - Google Patents

Description

Jan. 20, 1931. A. R. BAKER ETAL 1,789,615

PHOTOGRAPHIC LINE PRINT AND METHOD OI" MAKING THE SAUE Filed July 8, 1929 fix nvmvrons.

Patented 1 UNITED ST ES PATENT orrica ABTHU: B. BAKER AN D WALTER N. BAKER, OI OHIOAQO, IIJ JINOIS PHOTOGBAPHIC LINE PRINT AN D 1113301) HA IING THE SAME Application fled July], 1929. Serial in. 210,744.

The present invention relates to photographic line printing of the class wherein the work, that is, the delineations, or lines and dotswhich go to make u the image, is

. 5 placed upon a basic coating 0 collodion, lacquer, or like substance, and wherein said basic coating between the lines and dots is left exposed to atmosphere.

This class of printing is in contrast to that 1 where the sensitive coating, after being photographically' exposed, developed and fixed, is not removed, but is allowed to remain covering the basic coating.

Prints of the former class, as heretofore 115 made, do not present a surface u on which additions to the image may be rea ily drawn or written. Since it is the basic coating of collodion, lacquer, or the like, which must receive the ink or lead, if additions are to be made, it is obvious that such coating must be able to receive and retain the applied material; But in prior art prints of the class mentioned this has not been-the case; the basic coating will not satisfactorily receive and hold the added markings.

Another condition to be found in prior art prints of the class in question, is the brittleness of the structure of the work. By bending such prints back and forth a number of 'times at one point in the work, the latter may be badly mutilated. This mutilation is the 'result of the chipping off, or the breaking up, of the material ofthe work. Its rupture spoils the image.

The principal object of the present invention is to provide a new print of the class mentioned wherein desired additions may be readily made to the image and wherein the lines and dots, or either of them, constituting the work, may not be easil removed or mutilated in the manner pointe out. The invention includes not only the prints having these characteristics, but the method of producing the same.

In carryin out our invention, we start with -a prlnt aving the basic coating men-. tioned, and apply thereto a solvent of the.

basic coatin material, and then remove the resultmg so ution or softened mater1al,..so

as to bare the base between the lines and dots, the solution, meanwhile, being spread over .thes'e lines and dots to strengthen and protect them. The bared, or substantially ared, base can then be written or'drawn upon to enlarge or modify the image of the print, the base itself being suificiently free of the basic coating and being itself of such material that it will readily and effectively take the ink or lead of the additions. The smearing 'of the dissolved basic material over on the lines and dots, toughens and hardens them. The result is that the new print may be easily drawn or written, upon for the purposeof making additions to its image, and rough handling of the print does not to chip, break off, or otherwise mutilate the lines and the dots constituting the work originally on the print. 1

In our practice of the invention we have commonly applied'th'e same to prints formed upon a transparent or translucent base, and then the resulting print, produced in accordance with the present invention, can itself be used for making additional prints.

An important part of the present inven- '75 tionfwhich may have a wide application-in silver photography, resides in the fact that when the sensitive coatingwe have been describing is one containing a bichiomate with its holding qualities, and a silver salt, with its 3 light sensitive ualities, the solvent for the basic coating, w ich we have also mentioned, sufiices to fix the exposed delineations of the sensitive coatin without the need of the usual photogra hic s1 ver salt fixing solution, such 5 as hypo, erri cyanide of potash, and the like. The use of our solvent thus frees the product from many objections which result from the use of these chemicals.

Having presented these general views of the nature and character of the invention we may now pass-A20 a detailed disclosure of a. preferred embodiment of the same. This is. set forth in the following description and the accompanying drawing wherein the ste s of 96 the method and the character of the resu ting product are presented.' For the scope of the mvent-ion, reference should be had to the appended claims.

In said drawing, Fig. 1 is a' plan view. of a mo base coatedas heretofore described for the production of a print which will constitute the basis for the practice of our invention, portions of the coatings bein removed to show their relative positions; ig. 2 is a side elevation of the same, also showing ortlons of the coatings removed; Fig. 3 is a an view showin the'image developed and ed, and ready or the steps of our new method; Fig. 4 is a vertical section of said developed and fixed rint, the plane of section being 1nd]- cated y the line 44 of Fig. 3; Fig. 5 shows the previous structure treated by the basic coating solvent and showing the resulting dissolved material removed from the base between the lines, and spread over the work as a protective coating to the same, all as contemplated by the present invention; and Fig. 6 is asimilar view of the right-hand portion of the same structure illustrating the removal of material applied to, or impregnated in, the base as well as the removal of material of the basic coating. Throughout these views like characters refer to like arts.

The several views 0 the drawing are in measure diagrammatic. They also show the parts upon a greatly enlarged scale. All this is done with a view to clearness.

As previously pointed out the print structure which constitutes the basis for the application of our invention, consists of a base A, a first coating 13, and a second coating C. The base A may be composed of a stiff or flexible material. However, in the practice of our invention we find it desirable to employ a flexible material, commonly a fabric impregnated with starch, such as tracing cloth. Obviously, the flexible material may be either paper or cloth. The use of a translucent base, which'we commonly use, enables the resulting print to be used as a positive for printing other prints, as before noted.

The second coating B is a water-proofing coating of lacquer, collodion, compounds of lacquer, compounds of collodion, or mixtures of these materials.

The third coating 0 is a light sensitive coat ing having a bichromate as a. basic ingredient. Such bichromate may be a gum bichrom ate, a glue bichromate, a gelatin bichrom'ate, or an albumen bichromate. Indeed, any of the bichromates commonly employed in bichromate photography would be suitable for this basic ingredient. The other elements of the coating C may vary greatly, but they divide themselves into two classes, viz: those that include silver salts on the one hand, and those that inelude pigments and dyes on the other. As

illustrative of silver photography, these elements may be silver nitrate, silver chloride, potassium citrate, potassium bromide, potas sium iodide, ammonium bichromate, potassium bichromate, and sodium bichromate,

variously compounded. These mentioned elements are merely illustrative, and persons raphy development.

1,7ee,e16

familiar with silver photograph will appreciate the value of the difierent su stances, and will be able to combine these and others in suitable ways to give proper photogra hic results. As illustrative 'of the class emp oging pigments and dyes for bringing out t e image, we may refer to the ingredients mentioned in our previous Patent 1,704,356, dated March 5, 1929. As there pointed out, igments of different kinds for difi'erent co ors ma be used. The same is also true of dyes. Di erent dyes may be employed for different colors. In the resent case the coating 0, whether em loymg the pigments, dyes, or silver salts, includes one or more of the bichromates, as stated.

The structure built up by the base A and the coatingsB and C constltute a plate, film or the like, for the receiving of the photographic images. If the stri or sheet thus constituted is positioned bac of a negative having the image of Fig. 3 upon it, and the plate 1s properly exposed to light, then portions of the upper coating 0 will be acted upon by the light and chemically changed. Then as soon as the strip is properly treated the image will show forth, as in Fig. 3.

For the treatment of the pigment or dye coatinfg, in accordance with our a oresaid patent, it is only necessary to wash off the print with water. This washing will dissolve and carry away that portion of the coatin C which has not been chemically changed by the light. When it comes to treating the coating C where the latter includes a silver salt it is necessary to use a developer, such as is commonly used in silver photography, to produce a. change in the color of those'portions of the coating which has been acted upon by the light. In the the process of Y case of the silver compound, the image will remain just as in the case of the pigment or dye compound, but the silver salt requires the use of a developer which the pigment or dye does not. In both cases the washing of the print with water will carry away those portlons of the coating which are not fixed to show the image. This is clearly illus trated in Fig. 4 where the fixed portions C and C of the image stand up above the surface ofthe basic coating But, as we shall see later, when our solvent is used to remove the basic coating B, it is not necessary to use a fixing solution on the silver salts coating C. This is an incidental but novel feature in our silver photog- This point should be borne in mind when preparing silver prints for the subsequent steps of our invention. It may be noted, however,- that the use of hypo, ferricyanide and the like for fixing purposes prior to using the steps of our invention is not objectionable. Our method can be carried out just as well, and with just as good results, no matterwhether the fixer be used or not. But obviously its use, being unnecessary, better be omitted if the prints are to be sub'ected to the application of our solvent.

As as been indicated, a print, such as shown in Figs. 3 and 4, produced by any of to the portion C, for example, it is difficult to varied through a wide range without 0 do so because of the inability of the coating B to take and hold the substance applied or sought to be applied. Furthermore, if we consider the print in this form, it is easy, as before stated, to bend the, print back and forth and thus mutilate the material of the coating C which forms part of the image. This destroys the clearness of the image and hence reduces the value of the print.

In order to meet these difliculties, we apply to the surface of the print a solvent of the coating B. This solvent is preferably a mixture of alcohol and ether; commonly, one part by volume of alcohol is mixed with one part by volume of ether, although we have found in ractice that these proportions may be ec- -tionable results. We have also found that where the print is of the pigment or dye class, more alcohol may be used than ether. On the other hand, where the print is of the silver class the proportions just mentioned are preferable. Other solvents may also be employed if desired but the ones mentioned are quite satisfactory, being both effective and economica This solvent may be applied in different ways, A small piece of cotton batting dipped in the solution may be rubbed lightly over the surface of the print a number bf times and, preferably, in different directions. The effect is to soften up the material of the coating B and bring it practically into solution, depending, of course, upon theamount and strength of the solvent applied. The moving of the piece of batting over the surface will also wipe up the coating B from the surface of the base A between the lines and dots, and clean the same more or less perfectly at those points, while at the same time carrying the solution over the work already on the print. The effect is shown particularly in Fig. 5. There the coating B is practically removed at all points except where it underlies, or substantially underlies, the work C and C The surface of the base A is left bare, or practically so, wherever the coating B has been removed. As thedissolved material is removed from between the lines it is applied as a coating B to the work 0 and C as clearly illustrated.

Removing the basic coating B from between the lines has the effect of sharpening the edges of the lines. and brightening theprint; Often stains and sediment are resent in or lodged upon the coatin B an the cleaning of the coating from t e base removes all stains and sediment. The stains often come from photographic chemicals and the sediment is present in the form of visible particles embedded in the coating. The application of the solvent in the way described also takes away the shiny effect of the lines,

often present, and it may be applied so as to remove any sediment on the lines themselves.

Likewise, where the lines are too wide be-' cause of overex sure, they may be brought to proper width y repeating the applications of the solvent to the lines, usually brushing over them from the sides of the lines for this purpose as is done in photolithographing and other like work.

The application of the solvent to the coating B may be by wiping, as just described, scraping, spraying, or otherwise, as desired. It is only necessary in each of these methods to remove the dissolved coating from between the lines and to apply the same to the lines and dots.

Where the base A is coated or impregnated with a material which will be dissolved by the solvent of the coating B, as would be the case with tracing cloth, then some of the material of the coating, such as the starch of the tracing cloth, would be more or less mixed with the material which forms the coating B In such event the removal of soluble material from the base A will more fully expose the fibre of the base. An attempt has been made to illustrate this action in Fig. 6. There the dotted line 10 shows the original surface of the base and the full lines below it represent its surface after portions of the starch or like filling have been dissolved out and wiped away. The impregnating material thus wiped away mingles with the removed portions of the coating B to form the work covering B Obviously, a base A having no filling or impregnating material would not have its surface changed in this way and the coating B would be that which resulted'solely from the dissolution or softening of the material of the basic coating B.

The removal of the basic coating from between the lines also renders the finished print more pliable where it is made upon a flexible base A. This necessarily results from the removal of a large part of the basic coating B which is relatively stiff when thoroughly dried. Its removal also leaves the coated base thinner. The resulting greater flexibility of the print prevents the peeling off of the basic coating, as has so often been the CilSB heretofore with prior art'prints. of this 0 ass.

As incidental to the practice of our invention as just described, is the important fact that where the coating 0 is made up of silver salts in accordance with wellknown ractices in silver photography, the use 0 our solvent, as heretofore described, does away with the need of usin the fixin agents commonly em loyed in t at branc of photogra hy, suc as hypo and ferricyan-ide of otasl i. The use of our solvent upon: the silver salt coating C rforms the necessar" reducing and fixing unctions and renders t e print permanent without the use of the customary xing agents. This results in making the photographically rinted lines more permanent, as t ere wil be no traces of the hypo or ferricyanide left in the lines to cause the print to deteriorate as is commonly the case where they are used, the prints being bleached by the light as they ow old and the background becoming yel owish in color. So in s the case of the silver salts coating C, all that is necessary is to use the developer, water and our solvent; and in the case of the dye or ent coating C, merely use water and our vent. We do not sa that our solvent is a substitute for hypo an ferricyanide in-silver photography but it is such a substitute where the coating C is a silver salt compound on a produce coating of the character of coating B.

What we claimas new and desire to secure by a atent'ofthe United States is:

1. 'ihe method of producing a photographic line print of the class described, consist ng in selecting a base material capable of receivin and holding delineating marks by drawing or writing thereon, coating said base with a basic coating of material selected from a group, said group consistin of collodion, lacquer and compounds of coll work on said basic coating by photographic exposure of a light sensitive coating consisting of material including a bichromate, the portions of said basic coating between the parts of the work being made substantially bare and exposed to atmosphere, applying to the delineated work and basic coating a solvent of said basic coating material, and. removin more or less of the resulting solution from t e base between the parts of the work, to leave such portions of saidbase free for drawing or writing thereon.

2. The method of producing a photographic line print of the class described, consisting in selecting a base material capable of receiving and holding delineating marks produced by' drawing or writing thereon, coating said base with a basic coating of material selected from a group, said group consisting of collodion, lacquer and compounds of collodioii and lacquer, placing delineating work on said basic coating by photographic exposure of 4 portions 0 writing thereon.

odion and lacquer, placing delineating f a light sensitive coating consisting of material including a bichromate, the portions of i of the resulting solution from the base bem tween the parts of the work, to leave such said base free for drawing or 3. An article of manufacture of the class described com rising a base consisting of a material capa le' of receivin and holding delineating marks produced by drawing or writing thereon, hotographic line work on said base, the base eing free between the lines of said line work to receive said marks, and the structure of said photographic line work' comprising basic, intermediate and upper portions adhering to each other and the basic portion adhering to said base, said basic and upper portions including material chosen from a group, said group consisting of collodion, lacquer and compounds of collodion and lacquer, and said intermediate portion vconsisting of a fixed actinically modified sub stance. I I a 4. An article of manufactureyof the class described comprising a flexible baseof fibrous material "having a coating of starchy substance thereon capable of receiving and holding delineating marks produced by drawing or writing thereon, photographic line work;

on said base, the base being free between-the" lines of said line work to receive said marks,

and the structure of said photographic line work comprising basic, intermediate and up per portions adhering together and the basic portion adhering to saidbase, said basic and upper portions including material chosen rom a group, said group consisting of collodion, lacquer and compounds of collodion and lacquer, and said intermediate portion consisting of a fixedactinically modified substance, said basic and upper portions being mingled with said coating of starchy substance. p

5. The method of producing a photographic line print of the class described, consisting in selecting a base capable of receivin and holding delineating marksproduced by rawing or writing thereon, coating said basewith a basic coating of material selected from a group, said group consisting of collodion, lacquer and compounds of collodion and lacquer, placing delineating work on said basic coating by photographic exposure of a light sensitive coating which coating includes a photographic bichromate and a photographic silver salt and is, where unexposed to light, soluble in water, washing the ex-- solution and to leave the underlying basic coating bare, using a chemical photographic developer to bring out the delineations occasioned by the actinic action upon the sensitive coating, applying a solvent of said basic coating to said developed delineations and the bare portions of said basic coating to fix said delineations and dissolvesaid. coating, and finally removing more or less of said dissolved coating, to leave the portions of said base beneath the same free for drawing or writing thereon.

6. The method of producing a photographic line print of the class described consisting in selecting a base capable of receiving and holding delineating marks produced by drawing or writing thereon, coating said base with a basic coating of material selected from a group, said group consisting of collodion, lacquer and compounds of collodion and lacquer, placing delineating work on said basic coating by photographic exposure of a light sensitive coating which coating includes a photographic bichromate and a photographic silver salt and is, where unexposed to light, soluble in water, washing the exposed surface with water to remove the chemically unmodified portion of said sensitive solution and to leave the underlying basic coating bare, using a chemical photographic developer to bring out the delineations occasioned by the actinic actlon upon the sensitive coating,

applying to the develo ed delineations and the bare portions of sai basic coating a solution of alcohol and ether to fix said delineations and dissolve said basic coating, and finally removing more or less of said dissolved coating, to leave the portions of said base beneath the same free for drawing or writing thereon.

In witness whereof, we hereunto subscribe our names this 1st day of July, A. D. 1929.

ARTHUR R. BAKER. WALTER N. BAKER.

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