US842297A - Method of producing a combined line and half-tone printing plate. - Google Patents

Description

PATENTED JAN. 29, 1907. G. BRADT.

0. A. BON PILS & H METHOD DP PRODUCING 1. COMBINED LINE AND HALF TONE PRINTING PLATE.

APPLICATION. FILED NOV. 28, 1906.

2 SHEETS-SHEET 1.

T 11v VEN TORJ C, A Eon-( H5 mmIlll BYv - 'PATENTED JAN. 29, 1907. G. A. BONFILS & H. G. BRADT. METHOD OF PRODUCING A COMBINED LINE AND HALF TONE PRINTING PLATE.

APPLICATION FILED NOV. 28, 1906.

2 SHEETS-SHEET" 2.

I 1 UNITED STATES CHARLES ALDEN BONFILs A-ND HORACE e. .BRADT, QF'DENV-ER, .ooLoRADo.

PATENT OFFICE.

METHOD'OF Pnonucme A cemamzn um: Am) IHALETONE PRINTING PLATE; 1

tion. v

The invention relates to an improved process of producing combined line and half-tone printing plates, and has for its object t'o'obviate by the use of a simple mechanical process the laborious and skill-requiring method of lifting, cutting, and replacing the films on the negatives'now commonly employed to obtain the desired effect.

2 tone The various stepsemployed in practicing our method are illustrated in the accompanying drawings, in the various views of which like arts are similarly designated, and in which- Figure 1 represents the photograph or wash-drawingto be re roduced by the half:

process; Fig. 2, t e line-drawing to be repro need in combination with the photo graph or tint-drawing shown in Fig. 1 Fig. 3,

the two representations in combination ready uction Fig. 4, a negative photo- Fig. 3, t e linework being ainted out Fig. 5, a negative photographic plate of the line-drawing; Fig. 6, a reproduction of the latter upon the metal printing-plate; Fig. 7,

' the completed printing-plate, and Fig. 8 an impression taken therefrom. I

Referring to the drawings, 5 des'i ates a icture, such as a photograph or was drawmg, adapted to be re roduced by the halftone process, and 6 a ine-drawing executed for the purpose of zincographic reproduction and provided with diagonally-disposed registering marks 7. a

' The first step in our process consists in cutting-out those portions of the drawing 6 where on the finished'plate the half-tone work is toa pear, after which the skeleton mask thus 0 tained is placed in the desired position over the picture shown in Fig. 1, as illustratedin Fig.3. The combinedrepresentations are now reversedly reproduced upon a photographic plate by'means of a camera equipped with a prismatic lens. The

negative thus obtained isby interposition between the original and the lens of a screen,

Specification of Letters ratent. I Application filed November 28, 1906. Serial No. 345.621.

Patented Jan. 29, 1907.

adapted for photo-engraving, or, with other words, the solid tints of the original are represented on the plate b a multitude of juxtaposed dots or lines. Iii part of our invention it should be observed that in lieu of using a rismatic camera the negative may be made b means of an ordinary lens and the film su sequently lifted off such as commonly in half-tone work,

connection withthis and reversedly replaced upon the glass. plate.

The next step of our rocess consists in paintlng out the repro uction' of the linedrawing on the negative byfcoveringthe extent of the skeleton mask (with the exception of the registering marks) with indi'a-ink or other suitable opaque substance, as illustrated in Fig. 4. A second negative isnow made of the line-drawing to a scale identical withthat'ofthe image on the first plate by .method 0- removing t e screen from the frame in which the two representations are .photo graplhin the skeletonmask" placed upon a w :te ckg'round to obtain the effect o the ori inal drawin' or' by the simpler held and interposing a sheet of white paper As. the last named op.-

the' camera, it is obviously preferable to the. first-named method. The image on the lastmade. negative, which like the one on the I I first plate is reversedly produced thereon, is

now reproduced upon a zinc or copper plate previously coated withbichromate of ammonia or other sensitive substance by the ordinary method of placing the one upon the. other in a printing-frame and exposing the latter to the action of light. The sensitized surface of'the metal" plate (illustrated in Fig;

6) is now developed in the usual manner and preferably coated withphoto-engravers ink to render the impression, and more especially the re 'stering marks, discernible, after which t e plate is resensitized and replaced in the printingframe beneath the painted out negative, (shown in Fig. 4,) care being taken that the marks 7 on the negative and half-tone work, are reproduced upon the i I plate,with the result that when after exposure the plate is developed it contains, as illustrated in Fig. 7 the combined impressions of the photograph illustrated in Fig. 1- and the frame.

To thoseskilled in the art to which our invention pertains. its many advantages will be apparentas the method of coating the negative'with rubber and colodion and removing, cutting,-and replacin its film as heretofore employed has at al times been associated with such difficulties as shrinking, shriveling, turning under, and lapping of the films, the forming of air-bubbles between the film and the glass, &c., and can only be prac ticed by highly-skilled persons.

It will be understood fromthe foregoing that our process is adapted for the production of printing plates having either'an enamel or an albumen surface. g

Havingthus described our invention, what we claim is 1. The method of roducing combined line and half-tone printing plates, consisting in makin a negative bearing the reversed image of a photograph or tint-drawin and the reversed ontline reproduction of a inc-drawing covering the image of the line-drawing on the\ said negative with an opaque substance, producmg a second. negatlve bearing a reversed imageof the line-drawing, successively pro ducing prints of the two negatives upon a sensitized metal late, and etching the latter. g 2. The met 0d of producing combined line and half-tone printing plates consisting in skeletomzmg a line-drawing, making a re-, versed negative of the latter and the original photograph or tint-drawing, covering the image of the said skeleton upon the negative with opaque substance, producing a second, reversed negative of the line-drawing, sucoessively producing printsof the two negatives upon the sensitizedsurface of a metal plate, and etching the latter.

3. The method of producing combined line and half-tone printing plates consisting in skeletonizing a line-drawing, making a reversed negative of the latter and the original photograph or tint-drawing, covering the image of the said skeleton upon the negative with opaque substance, producing a second, reversed negative of the-line drawmg, producing a print of the last-named negative upon the sensitized surface of a metal plate, developing and resensitizing the latter, producing a print thereon from the first negative, and etching the plate.

In testimony whereof we have affixed our signatures in presence of two witnesses.

CHARLES ALDEN BoNFILs'. HORACE G. BRADT.

Witnesses:

' WM. H. EADER.

FRANK M. STORES.

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