US774528A - Manufacture of plates for printing. - Google Patents

Description

No. 774,528. PATENTED NOV. 8, 1904. E. A. NEBEN.

MANUFACTURE OF PLATES FOR PRINTING.

I APPLICATION FILED APR. 6, 1904. NO MODEL.

WITNESSES: INVENTOR 5 lzweaifi ./7/6 67Z y K BY ATTORNEYS? UNITED STATES Patented November 8, 1904.

ERNEST A. NEBEN, OF NEW YORK, N. Y

MANUFACTURE OF PLATES FOR PRINTING.

SPECIFICATION forming part of Letters Patent No. 774,528, dated November 8, 1904:.

Application filed April 6, 1904- T0 (I/ZZ whmn it may concern: I

Be it known that I, ERNEST A. NEBEN, a citizen of the United States, and a resident of the city of New York, borough of Brooklyn, in the county of Kings and State of New York, have invented new and useful Improvements in the Manufacture of Plates for Printing, of which the following is a full, clear, and exact description.

The invention relates to the art of preparing relief-plates for printing 'typographically therefrom.

The object of the invention is to provide certain new and useful improvements in the manufacture of plates, whereby zinc or copper plates are produced for receiving any desired design in half-tone effects, together with the necessary contrast of high lights, solids, and shades to allow of using the plates for the reproduction of color work for fine colorprinting.

The plate consists of a metallic body having a polished face and a grain, dots, stipples, or the like on the said face and formed by an acid-resisting substance hardened by being burned on the said face, the said grain, stipples, dots, &c., permitting the artist to apply the design by the use of transfer-paper and to stop out desired portions by an acid-resisting substance, which allows an etching of the plate, a number of such plates being treated corresponding to the number of the colors in the original design.

In detail I proceed as follows, special reference being had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the views.

Figure 1 is a side elevation of a zinc or copper plate having a polished face. Fig. 2 is a similar view of the same, showing the polished face coated with the sensitized substance. Fig. 3 is a like view of the plate, having the coating and a screen superimposed on the coating. Fig. A is a side elevation of the plate provided with a field. Fig. 5 is a side elevation of the heater for heating the plate to indurate or harden the field on the plate. Figs. 6, 7 and 8 are sectional side elevations illustrating the successive steps for producing the Serial No. 201,841. (No model.)

printing-plate, and Fig. 9 is a sectional side elevation of the finished printing-plate.

The polished face of a Zinc, copper, or similar metallic plate A is provided with a thin coating B of a sensitized substance such as is used on ordinary photographic plates or films. Anegative C, representing dots, lines, stipples, cross-cut lines, grain, &c., is superimposed on the coating B, and both the negative and the plate A, with its coating, are then subjected to an exposure of light, after which the negative is removed and the plate is washed to remove the soluble portions of the coating and to leave an insoluble field B in the form of dots, lines, stipples, cross-cut lines, grain, &c., according" tothe nature of the negative C used. The plate A is now preferably subjected to heat to indurate and harden the field B, represented by the dots, stipples, &c. The heating is-preferably done on a heater, such as shown in Fig. 5, and which consists of a grate D for the plate A to rest on and gas-burners D below the said grate. The plate prepared as described is now ready for the market; but it is understood that if the plate in'its present condition were used in printing it would produce a solid impression.

In order to use the prepared plate for making a printing-plate for color-work, for instance, the user proceeds as follows: For the production of a four-color design, for instance, it is necessary to make three impressions on lithographic transfer-paper from a key-plate, and the impressions are then transferred on three plates prepared as above described. The artist with the aid of a brush or the like now treats 'each plate separately, according to the color to be reproduced, and applies an acid-resisting substance Esuch as asphaltum varnish-{see Fig. 6) on the portions representing the solids pertaining to the respective color of the original design, and then the plate is subjected to an etching agent in the usual manner, whereby the acid attacks only those portions in the polished face of the plate A that are not covered by the said dots, stippies, &c., forming the face B and the acidresisting substance E. ,(See Fig. 6.) By this treatment the face B of the plate A is left with the solids B and very flat dot portions B printing heavy dots to the strength of the color desired when the plate is used in printing. In order to produce half-tone tints or somewhat lighter dots B, as called for by the original design, it is again necessary for the artist to apply an acid-resisting substance E (asphaltum varnish) onto the portions of the fiat printing-face desired to remain in the plate to protect the said portions from the second acid-bath to which the plate is now subjected. The acid now eats away on all the sides of the dots, stipples, &c., of the plateface not covered by the acid-resisting substances E E, thereby rendering the plate-face portions located under the uncovered dots, stipples, &c., smaller and rounder, and forming the cross-lines in the plate-face deeper and wider until the desired half-tone tint B is reached. As the original subject-matter also calls for some very light tints B, it is necessary for the artist to stop out corresponding portions of the half-tone tint B by the use of an acid-resisting substance E (asphaltum varnish,) and then the plate is again subjected to an acid-bath to again reduce the face portion under the remaining non-covered dots, stipples, &c., to form exceedingly fine sharp dots, stipples, &c., in the face of the plate A. The parts of the face not desired to print at all are now routed out or otherwise removed, as indicated at B in Fig. 9. As the field B is exceedingly thin, it is evident that as the acid of the different baths eats away portions of the plate-face under the dots, stipples, &c., of the field B their overhanging edges crumble or break, and only the portions on the polished non -acid attached portions of the face of the plateAremain and form an enamel or indurated hardened printing-face on the plate A. Each of the plates is treated, as above described, according to the color to be printed by this particular plate-that is, the solids B for this color are first stopped out. Then the plate is subjected to an acid-bath to produce portions B printing to the strength of the color. Then a portion of the portion B is stopped out and the plate subjected to an acid-bath to form half-tone tints B, a portion of which in turn is stopped out and the plate again subjected to an acid-bath for producing high light tints, such as at B and the portion B not to print at all is finally routed out or otherwise bodily removed by suitable tools in the hands of the artist. It is understood that the successive stopping-out and subsequent etching processes of the plate may be carried on any desired number of times to produce all the gradations in tone called for by the original subject-matter to be reproduced. The portions E E and E of the acidresisting substances are now removed by washing the plates or otherwise treating the same, and then the plates are ready for use in the printing-press to reproduce the subject in four colors.

It is understood that the field B on the face of the plate A, and consisting of dots, stipples, grain, or the like is sufficiently indurated or hardened to resist fracture or marring while the plate is in transportation or is treated by the artist, as above described. By indurating or hardening the field the latters holding property on the face of the plate A is increased to such an extent that the field adheres persistenly to the plate-face to allow carrying out the processes of stopping out, etching, and printing without danger of displacement of the dots, stipples, 620'. Although I have found it expedient to indurate or harden the plate by the application of heat, I do not limit myself to this process, as other means may be employed to produce the same resultthat is, to provide the polished face of the plate with an enamel printing-field of dots, stipples, &c.

It is understood that, if desired, the enamel printing-field B, shown in the finished printing-plate, Fig. 9, may be removed by Washing the plate with a suitable solution or otherwise treating the plate for the purpose, andv in case such field is removed the plate will print the same as with the field B left thereon on account of the solids, half-tones, and gradations thereof now being integral parts of the polished face of the printing-plate. In practice, however, I have found that it is not necessary to remove the printing-field B.

Having thus described my invention, I claim as new and desire to secure by Letters Patent The herein-described process for producing relief-printing plates, consisting in photographically producing a field of insoluble matter on the face of a plate, indurating the said field, to harden the same and cause it to adhere to the plate-face, then transferring the subject-matter of the design onto the said field, then alternately stopping out portions of the field and plate and etching the same, and finally removing the stopping-out substance from the face of the metal plate.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ERNEST A. NEBEN.

Witnesses:

THEo. Gr. HOSTER, EVERARD B. MARSHALL.

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