US753746A - Method of preparing color-plates for printing. - Google Patents

Description

No. 753,746. PATENTBD MAR. 1, 1964.

c. N. SMITH.

METHGD 0F PREPARING COLOR PLATES IOR PRINTING.

APPLICATION IILEDJAN. 10. 1 903.

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-PATBNTED MAR; I',`19o4. o. N. SMITH. METHOD 0T PRBPARING GoLoR PLATES FOR PRINTING.

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APPLICATION FILED JAN. 10. 1903.

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UNITED STATES Patented March 1; 1904.

PATENT OEEICE.

CHRIS N. SMITH, OF ELCrIN, ILLINOIS, ASSIGNOR TO THE DAVID C. COOK PUBLISHING COMPANY, OF ELGIN, ILLINOIS.

METHOD OF PREPARING COLOR-PLATES FOR PRINTING.

SPECIFICATION f01 m11g part 0f Letters yPatent No. 753,746, dated March 1, 1904.

Apphcation filed January 1o, 41903.

To all whom it mag/concern.-

Be it known that I, CHRIS N. SMITH, residing at Elgin, in the county of Kane and State of Illinois, have invented a new and Improved Method of Preparing Color-Plates for Printing, of which the following is a specification.

and by which the plate can be wholly prepared without the aid of skilled labor and the engraving and etching done by hand by eX- perienced engravers, required in the present methods of preparing color-plates, is entirely dispensed with.

As is well known, in the methods now commonly employed for preparing color-plates for letter-press printing it is usual to transfer all colors on a separate plate, which is.

g plates are half-tones or solid, the filling a has then engraved and etched before it may-be ready for electrotyping.

My improved method in its generic nature differs from the methods now generally employed in that no etching or engraving of the plate is required and in thatthe treatment of the plate is such that it is made possibleand perfectly practical to make from one to four colors by my process.

With the above and other objects in mind my invention consists in the method of preparing a relief-plate for color-printing, hereinafter fully described, and specifically pointed out in the appended claims.

In order that my invention may be better understood, attention is directed to the accompanying drawings, in which- Figure 1 shows a portion of an original relief-plate for letter-press printing which may be in the nature of an electrotype, stereotype, or an ordinary type-form. Fig. 2 is a representation of the plate shown in Fig. l after receiving the first step of my method-that of Serial No. 138,542. (No specimens.)

applying the composition for filling the face of the plate at the places where it is intended to make the color impressions. Fig. 3 shows the said plate after it has received the second step of my method-that of cleaning away the filling at the desired points. Fig. 4 illustrates a slight modification of my method; and Fig. 5 is a section of a portion of a plate constructed in accordance. with my invention with the filled surfaces a", hereinafter referred to, in a plane parallel with but slightly higher than the remaining surfaces of thev plate.

Fig. a'isasection of a portion of a plate,

illustrating a part of the filling cut away for the purposes hereinafter explained. f

The original plate, either an electrotype, a stereotype, or an ordinary type-form, is filled at the points where it is desired to have the imprints in colors with wax or any other composition that will stand the heat like wax. -A .This filling (indicated by a) is then smoothed o down in aparallelplanewith the printing-sur` face of the plate and is preferably built up a little higher than thesaid surface, as diagrammatically indicated by w in, Fig. 5. When the its surface a burnished smooth, as shown, at

. the parts l la, whereby to present a solid inktaking surface; but where the cuts or designs i are open the wax from that part thereof not intended to appear in color is cut away down `to the metal surface l, as indicated by 2 in So far as described it will be readily apparent that by reason of having `to remove the soft filling rather than the hard metal a great advantage is obtained over theoldmethod, in

which the cutting away of the metal is 'necessary to eliminate from the plate the impression-surface not to appearcolored in the print, it being obvious, however, that `in the event of the built-up portion or filling a .being shallow-that is, its outer or impression surface being substantially iush with the metal impression-surface of the plate-the metal at the blank or open spaceszfrom which the wax lilling is to be removed may also be cut away to have the desired results, as shown in Fig. 4.

When the cuts of the plates are solid-that is, when it is desired to print a solid color entirely over the cut or illustration indicated by 5 in Fig. l-the wax filling is smoothed off solid with the printing-surface of the cut, so as to completely fill all Vof the white7 spaces or stippled indentations when the cutis a halftone, and the said surface is burnished whereby to produce, as it were, a solid smooth printing-block, as indicated by 5 in Fig. 3.

Another important advantage incident to my method is that by pressing a screen on the wax or composition filled in on the original plate the color-printing surfaces may be stippled or screened fine or coarse, as desired, and exactly the same results obtained lthereby as would be the case were the old method employed-that is, stippling or screening the said color-printing surfaces by the aid of an engraving-tool or etching-and the said result is obtained without the aid of skilled labor, as

the skill of an engraver or etcher is thereby entirely dispensed with. One of the screens or stippled surfaces is indicated by 5X in Fig. 3.

After the original plate is treated in the manner before described a copper shell thereof is formed by electrotyping in the usual way, since the composition or filling a hardens when it sets, so as to permit o f electrotyping. The electrotype-shell is then backed up and finished, as would be the case with an ordinary electrotype-plate, the difference between the old method and my method of producing color-plates being wholly in the preparation of the plate for the color-work.

Since in the present method of preparing color-plates it is necessary to transfer all colors on a separate plate, which plate is then engraved or etched before being ready for electrotyping, it follows that as the said requirements are not necessary in my method a great saving of time is effected in making the form ready for color-printing, for the reason that in my method the work of removing those portions of the plate not to appear in color on the print is done in wax or other composition and easily scraped away from the hard metal. The expense of preparing the plate is by my method greatly reduced, as in the practical application of the same Iliave found it possible to turn out twelve plates by my method in the time required to turn out one plate by the old method.

' Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

l. The method of preparing an original relief-plate for the purposes described which embodies the following steps: first, applying a filling of wax or other similar composition to the surface of the said original relief-plate, smoothing the said filling in the plane parallel with the said surface; second, removing' the said filling from those parts of the original relief-plate not to appear in color on the print ,which may be made from the plate, as set forth.

2. A method of preparing an original reliefplate for the purposes described, which consists in, first, applying a layer of yielding plastic material, capable of resisting heat, and smoothing said material 'in a parallel plane with and slightly above the printing-surface,.

and second, removing the said material from those parts of the plate which are not to appear in color, upon the print which may be made from the finished plate, as specified.V

3. A method of preparing an original reliefplate for the purposes described-which consists in, first, applying a filling of plastic material capable of resisting heat on the printfilling on the impression-surface thereof which 1 covers all that portion of the plate to be utili ized as a color-printing surface, as set forth.`

6. A relief-plate of the character described, having a plastic filling on aportion of the 'impressionsurface Whose printing-face is in a plane parallel with and slightly above the remaining portion of the impression-surface of the relief-plate that is free of the filling, as

set forth.

CHRIS N. SMlTH'. Witnesses:

Gr. B. RICHARDSON, LoUIs H. POTTER.

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