US1785922A - Method of making cloth stencils for multicolor work - Google Patents

Description

R. TULL Dec. 23, 1930.

METHOD OF MAKING CLOTH STENCILS FOR MULTICOLOR WORK Filed Sept. 11, 1,928 2 Sheets-Sheet l 7 INVENTOR.

Dec. 23, 1930. R. TULL 1,785,922

METHOD OF MAKING CLOTH STENCILS FOR MULTICOLOR WORK Filed-Sept. 11, 1928 2 Sheets-Sheet 2 IN VEN TOR. Rage! ZZZ,

041/ MA TTORNE YS.

Patented Dec. 1930 UNITED STATES JBOGIB TULL, OF LOS ANGELES, CALIFQBm- ASSIGNOB TO W'ESTEBN LITHOGRAIH PATENT OFFICE COMPANY, OF LOS .AIHGELES, CALIFORNIA, A CORPORATION OF CALIFORNIA imrnon or mme c orn srmicrLs roa mnconon woax Applicationfiled February 11, 1928. Serial ms. 253,764.

. This invention relates to methods of making cloth stencils for multi-color work, and, more especially, to that type of stencil that employs bolting cloth, or equivalent fabric, through which paint is forced onto a sheet of paper or other surface that is to receive the print. w

An object of the invention is to improve the method disclosed in my former Patent No. 1,622,747 dated March 29, 1927.

This invention makes it possible to prepare stencils photo'graphically from anoriginal in which some of the colors to be reproduced have photographic color values that are not markedly difl'erent. a

This method is especially useful in the ref production of crayon originals as by it the Fig. 5 represents a print on crayon efiect is reproduced.

The accompanying drawings illustrate some of the operations of the new method and the product resulting from the same.

Fig. 1 represents a colored original that is to be reproduced, the difierent colorsbeingi only indicated in black and white.

ig. 2 represents a negative plate photogrsliiphed from the origina in Fig. 1.

ig. 3 represents a sitive plate made from either the origina shown in Fig.1 or the negative shown in Fig. 2.

Fig. 4 represents a print. on sensitized screen fabric from the positive sensitized screen fabric from.- the negative shown in firepresents a stencil resulting from blockm out-the print shown in Fig. 4.

Fig. represents a stencil resulting from blocking out the print shown in Fig. 5. Fig. 8 represents a print made by using the stencil shown in Fig. 6. I Y

Fig." 9 represents theprint shown in Fig; 8 after it has received an impression by use of the stencil shown in Fig. 7

5 a colored original, such as that represented inclose contact with the sensitized bolting 00 Fig. 10 represents theeompleted reproduction, sho all the colors-contained in the original, sai colors being simply indicated in black and white. p 7' g To perform the method of this invention,

shown in in Fig. 1, is photographed on asensitized plate, in a manner well understood in the art pertaining to photography and the result is a negative such as that indicated in Fig. 2. Preferably, to get as strong color contrast values as is possible the photographic negative will be made by the, use of the wellknown color screen or screens or, at least, it is advisable to employ a light sensitive plate that is panchromatic.

. After this operation a. photographic positive will be prepared of the same subject and said positive may be made by photographing through the negative in Fig. 2 upon a sensitized platewhich, also, is preferably panchromatic. This positive is represented in Fi 3. I The next operation is to make photographic\ prints fromthe negative and positive on sensitized screen fabric such, for example, as bolting cloth which is usually employed where paint is to be forced through it for making prints. The term bolting where-,

ever employed in this description defines any fabric suitable foruse as a stencil screen. 7

The photographic prints mentioned above may-be made as follows: No. 14XX bolting cloth is stretched over the edge of a wooden frame and the cloth thus stretched is taken to a darkroom, and acam'el hair brush is employed for covering the bolting cloth on the outer side 'with a solution made as follows: 90 grains of bichromate of ammonia is dissolved in 6 ounces of distilled water and this mixture will be identified as mixture A. 2. ounces of liquid glue are mixed with the white of one egg or albumen egg merck and this will be identified as mixture B. 'x-

tures A and B thus produced will then be 3 thoroughly stirred togetherand 10 drops of aqua ammonia added and this mixture will about an hour, the sensitized cloth is ready for printing from the negative.

- For printingy'the negative will be placed cloth and then exposed, say for minutes in front of two 500 watt lamps. After thus portlons of the bolting cloth'of the water.

Those portions of the sensitizer rendered insoluble in water by the action of light will not be washed off.

After this treatment, the printed bolting cloth will be placed in the sunlight until the sensitizer that remains hardens. This takes about 10 minutes. If there is no sunlight, it

should dry in a place free from dust.

The print resulting from printing through the positive shown in Fig. 3 is indicated in Fig. 4 and the print resulting from printing through the negative shown in Fig. 2 is indicated in Fig. 5. For clearness of description these prints on fabric will be termed herein screen prints. It is to be understood that there will be one screen print made for each color that is to be reproduced. For example, assuming that the original is in twelve colors, six screen prints will be made from the negative and six from the positive. By having prints made from both negative and positive plates, the blocking out of the color areas that it is not desired that the paint pass through is facilitated as will be made clear hereinafter. The actinic action of the light, on those portions of the sensitizer that are exposed to the light rays passing through the plates, hardens said portions and thus photographically blocks out certain areas on said plate. Thus, it will be seen, that the photographically blocked out areas on the positive prints are those areas that correspond to the colors having the lesser actinic values in the original; and that the photographically blocked out areas on the negative prints are those areas that correspond to the colors having the greater actinic values in the original.. Thus the positive prints will have clear portions so that paint will pass through to render the colors of relatively high actinic value, while the negative prints Wlll have clear portlons for the passage of paintto render the colors that have relatively low actinic value. Two such stencils are represented in Figs. 6 and 7, that in Fig. 6 representing the stencil-produced by blocking out the stencil print 4 and,

that shown in Fig. 7 being the result of blocking out the print shown in Fig. 5. It is to be understood that if the printing is to be done in twelve colors it will be necessary to block out on twelve screen prints so as to produce twelve stencils since some of these stencils will be the result of blocking out on the positive prints and some from blocking out on the negative prints. The advantage of making prints from both positive and negative plates will now be seen for, in order for paint to pass through any givencolor area, said area must have its mesh or pores open. To obtain the open pores for some colors, prints from the negative are required whereas to obtain open pores for other colors, prints from the positive plate are necessary. This will be readily understood by referring to Figs. & and 5 of the drawings. In Fig. 4 which represents a print from the positive plate, the area 11 is open for the passage of paint of one color and in Fig. 5 which represents a print from the negative plate, the corresponding area 110 is closed so that paint of a different color cannot pass through said area. Another reason for employing prints from both positive and negative plates is that the artist can the more readily distinguish between certain colors in the blocking out of the prints for producing stencils for the different colors.

After the screens have this manner, they will be treated with lacquer mixed with No. 206 Zapon blue and No. 16 Zapon thinner, or other suitable nitro-cellulose products. This solution is applied on one side of the screen with a large brush and, at the same time, the other side of said screen is rubbed with a soft rag.

The stencils having been produced as above described concludes the new method. The stencils will be employed in a manner well understood in this art by forcing wet paint through the open area of one of the stencils onto the surface that is to receive it and, after the paint on said surface is sufiiciently dry, another stencil for a different color will be laid over the printing surface and a different color of paint pressed through the second stencil upon said surface or/and upon a portion of the first printed color. Thus, all of the stencils for the different colors will be used successively and the resulting product is shown in Fig. 10 which is virtually I. duplicate of the original shown in Fig. 1.

From the foregoing it will be readily understood that I have discovered how to re produce a crayon or pastel original that is in many colors so as to obtain an effect that, at a slight distance, cannot be distinguished from crayon or pastel work. Itis practically impossible to show in pen and ink drawings the peculiar and extremely pleasing effects that can be produced by this method to resemble crayon pictures. However it will be greatly appreciated by those skilled in the art that the simulated strokes of the crayon that can be obtained by this method the more closely resemble crayon or pastel strokes on crayon paper because of the more or less jagged effect secured by forcing the paint through bolting cloth, a form of stencil that is now widely used.

I claim:

The method of making cloth stencils for multi-color work consisting in making a photographic positive plate and negative plate been prepared in Mill from the colored original that is to be reproduced, making photographic prints on sensitized bolting cloth from the positive and negative plates, blocking out on the print from the positive plate an area that is to be impervious to paint and that corresponds to one of the colors that photographed dark on the positive plate, and blocking out on the print from the negative plate an area that is to be impervious to paint and that corresponds to one of the colors that photographed dark on the negative plate.

Signed at Los Angeles, California, this 23 day of January, 1928. v ROGER TULL.

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