US1577181A - Method of producing intaglio printing plates or cylinders - Google Patents

Description

Patented Mar.'16, 1926.

UNITED STATES PATENT OFFICE.

WILLIAM EDWARD QBOWE, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE PRISMATONE COMPANY, INC., OF CHICAGO, ILLINOIS, A. CORPORATION OF NEW YORK.

METHOD OF PRODUCING INTAGLIO PRINTING PLATES OR CYLINDERS.

No Drawing.

the production of such printing plates or cylinders may be greatly expedited and whereby more accurate color control or color rendering with a marked improvement inthe resultant printing over that which is possible in the use of methods. now commonly employed may be attained.

It is another object of my present invention to provide such a method whereby the etched cavities in the surface of the printing plate or cylinder will be of uniform depth for both the high-lights and shadows, thus resulting in the deposit of a uniform quantity of 'ink on the paper during the entire commercial life of the cylinders or plates as distinguished from the present method wherein the high-lights gradually disappear from the printed sheet because the etched cavities are much shallower than the cavities for the shadows or darker portions of the print and therefore, wear away more quickly so that in a relatively ,short period of time no ink will be deposited fromthese shallow cavities on the paper. As a result, I secure a much greater'volume of production since the whole surface of the copper plate or cylinder wears evenly due to the fact that all of the cavities are of the same depth.

It is also another object of my present improvements to provide such a method wherein the ordinary half-tone and Benday relief printing plates may be used in place of photographic positives for the production of the relief portions of the half-tone and 'Benday plates inthe form of etched cavities in the surface of the final print ng plate or cylinder of uniform depth.

I shallnow first describe a preferred embodiment of my new process or method and then subsequently-describe an alternative thereof.

Serial No. 1,498.

The impression or impressions for printing in color is first produced upon individual half-tone or Benday process plates in the same manner as now employed. After a satisfactory plate has been obtained for'each color, I then take this original plate corresponding to either yellow, red, blue and black respectively and black ink each respective plate. Then I apply directly to each inked plate, a transparent material and thus take an impression from each plate on grained, ground, or coated celluloid or other transparent impression. receiving material. This provides a separate black proof on this celluloid or other transparent material of each color.

This transparent material proof is used as a photographic printing medium and the impression thereof is transferred directly from each of these proofs to separate carbon tissue sheets by means of lights. The impression from each of said carbon tissue sheets is then transferred directly to the individual cylinders or final printing plates. Each carbon tissue corresponding to each color is for each separate cylinder or plate.

In order to be able to duplicate cylinders to enable such duplicated cylinders to be substituted for the first cylinders, the same transparent material proofs can be used again for new carbon tissues, to be applied to other cylinders or plates whereby duplicate cylinders or plates can be made.

This celluloid or transparent proof material is a master sheet from which any desired number of carbon sheets may be produced for the purpose of making any number of duplicate cylinders or plates.

In the present state of the art, glass plates; are used which require re-touching and if broken, it is impossible to make an exact duplicate. But by the use of the celluloid proof, each carbon tissue will be printed exactly alike and hence each cylinder made therefrom exactly alike.

In the process at present commonly in use, photographic negatives are made, these are retouched, then photographic positives are made from these retouched negatives and then these positives have to be retouched. Such retouching of the positive and negative prints is unsatisfactory because proper color rendering on the negatives and positives requires the highesttype of skilled ar-' tists, and there are no establishments supply- I ing commercial printing plates and cylinders where printers might obtain work of this kind. On the other hand, any printer employing my new method can purchase the half-tone and Benday process plates. Therefore, it will be seen that one of the prominent features of my present improvements resides in the application and use of half tone and Benday process plates to the intaglio method of printing. Another objection to the present method is that the retouching of the negatives and positives is not satisfactory because they are of continuous tone and therefore, the artist has no gauge or measure by which to proceed and must depend upon his own judgment. The only retouching required in the present method is upon the etched plate or cylinder. The retouching on the copper plate or cylinder is much more satisfactory than the retouching on positive and negative prints, such retouching of the etched cylinder corresponding to color photoengraving which I apply to intaglio printing.

Another advantage incident to the use of color half-tone and Benday process plates which is one of the oldest known methods of color rendering resides in the fact that color etchers are accustomed to arriving at certain color schemes in terms of the different size or area of the dots or screen forma tions on such printing plates. In other words, I have succeeded in applying the oldest and most satisfactory method of plate making to the most modern kind of print ng.

In the case of intaglio printing, the impressions thus transferred to the cylinders or plates are then etched out in the surface thereof. However, it is to be understood that my new method is not necessarily limited to intaglio printing, but can also be applied to off-set and photolithographic offset printing.

From the above; it will be noted that by means of'this method, I eliminate entirely the necessity for all camera work, and all re-touching. In other words, negatives and positives are not made from the half-tone or Benday plates. Consequently, I am onabled to maintain directly absolutely tone values and screen formations of the original plates thus proofed on celluloid or other suitable transparent material. I sometimes find it beneficial to use in connection with the above described method, a screen on the carbon tissue before rinting thereon.

As an alternative or the above described method, I may take the original yellow, red, blue and black half-tone or Benday plates and make a black proof on celluloid or other transparent material for one color or each one of the four or more colors, and then photograph each of these black proofs, this producing four negatives. From these four negatives, I make; a positive of each color print. This results in absolutely perfect control of the color as distinguished from the uncertain results obtained by the use of the present method, wherein it is necessary to re-touch the negative and positives. From the four positives thus obtained, I print upon the four separate carbon sheets by the same method as now in general use, and in connection therewith I may also use a screen as above referred to in the description of the preferred embodiment of the invention.

From the foregoing it will be seen that by the production of intaglio printing plates or cylinders by the present method using relief process printing plates such as halftone and Benday plates, more uniform and consistent printing will be produced by reason of the fact that the etched cavities are of uniform depth in both the highlights and shadows, thus depositing a uniform quantity of ink on the paper during the entire life of the cylinder or plate. The operation of etching, therefore, becomes a mechanical operation requiring no great skill 011 the part of the etcher, since the cavities in reality are merely the inverted half-tone dots of the half-tone or Benday plate. I have foundfrom practical experience that by reason of the uniform depth of the etched cavities, the most satisfactory results are obtainable by an etching operation consuming less than one-half the time heretofore necessary in the production of intaglio printingplates. As, in such printing plate the uniform depth cavities wear away evenly, duplication of the printing cylinders or plates for large quantity production work becomes unnecessary.

It is to be understood that the present process may be practiced with distinctly advantageous results in the expedition of the work, either as applied to monotone or multi-color printing. In other words, it will be evident from the foregoing description of my new method for the transfer of the impression from the original half-tone or Benday process plate or plates 'to the transparent proof material, and thereafter as described to the final plates or cylinders or printing plate or plates is greatly ex-f in time.

pedited and an appreciable savin and labor is realized by the elimination of the necessity for re-touching positives and negatives, While, at the same time, more positive and correct color control or color rendering is attained with a corresponding improvement in the final multi-color impression. This is due to the fact that each cylinder or plate for each color, in case more than one color is used, is an exact duplicate of each of the others and that by the use of a transparent impression receiving material for the transfer of the impression from the black proof, of the half tone or Benday process plates to the carbon tissue sheet, all of the high lights and the sharp details are retained and not obliterated or lost, as is the case when the photographic process is used.

I claim: I

1. An improved method of producing intaglio printing plates or cylinders which consists in first producing an impression upon a transparentimpression receiving material from a relief process printing plate; then photographically reproducing the said impressionfrom said transparent material on carbon tissue, then applying the carbon tissue upon the surface of the printing cylinder or plate, and then etching the surface of the cylinder or plate through said carbon tissue and producing uniform depth cavities therein.

2. An improved method of producing intaglio printing plates or cylinders which consists in first producing an inked impression from a half-tone printing plate upon a transparent impression receiving material, then photographically reproducing such inked impressiop from said transparent material on a carbon tissue sheet, and then etching through said carbon tissue sheet upon the surface of the printing plate or cylinder to produce uniform depth cavities therein for all parts of the image.

3. A method of producing intaglio printing plates for multi-color printing which consists in first producing an inked impression from each one of a plurality of relief process printing plates upon transparent impression receiving material, then photographically reproducing the respective impressions on separate carbon tissue sheets, then transferring the carbon tissue sheets to separate printing plates or cylinders, then etching the surfaces of the respective plates or c linders through said carbon tissue sheets or the purpose of print ing in intaglio therefrom.

4. The method of producing intaglio printing plates or cylinders WhlCh consists in first producing an inked impression from a relief process printing plate upon transparent impression receiving material, then photographically reproducing the impression from said material upon a carbon tissue sheet having a screen printed thereon, then transferring the carbon tissue sheet to the surface of the plate or cylinder, and finally etching through the carbon tissue sheet to produce uniform depth cavities in the surface of the cylinder or plate for the purpose of printin in inta lio therefrom.

5. In the r0 uction o intaglio printing plates or cy inders, the steps which consist in photographically reproducing upon a carbon tissue sheet relief dots of a commercial half-tone printing plate and then etching the surface of the plate or cylinder through the carbon tissue sheet to produce uniform depth cavities therein for the purpose of printing in intaglio from the plate or cylinder.

6. In the production of intaglio printing plates or cylinders, the ste s which consist in producing a photographic impression of the relief portions of a commercial printing plate upon a carbon tissue sheet without retouching, and then etchingthe surface of I a printing plate or cylinder through said carbon tissue sheet to produce uniform depth cavities therein corresponding with the relief portions of the commercial printing plate for the purpose of printing in in taglio therefrom.

In testimony that I claim the foregoing as my invention, I have signed my name hereto.

WILLIAM EDWARD CROWE.