Printing plate

“ The plate can then be rolled with ordinary printing-ink, and impressions taken to any reasonable amount.
Space will not permit us to detail the various modifications of this process which exist under different designations. Metal plates can now, by a very similar treatment, be made ready for the etching acid. Wood-blocks which no artist but the sun has touched, can be given to the engraver ready to his hand. The lithographic printer is also independent of the draughtsman, for absolutely perfect fac-similes of maps, plans, &c.; line-subjects can also be produced in endless quantity. ”

“ A second branch of the art is plate printing, in which the lines and characters are engraved in intaglio in a plate, and which, being covered with ink, and the surface of the plate wiped clean, leaves the ink in the undercuts, which is taken up by the paper when pressure is applied through a roller. Plate printing is a very old art, the plate printing press having been ascribed to Tomasso Finiguerra, of Florence, in 1460. ”

“ In the ordinary type of litho-printing machine the printing bed (Fig. 22) is levelled in the machine for the first printing, and, if this is carefully arranged, no alteration will be required throughout the whole series; for, in changing from one colour to another, the printing plate can be slipped from the bed and another substituted in a very few minutes. The most scrupulous care should be exercised at all times to prevent dirt or grit of any kind insinuating itself between the surface of the printing bed and the back of the plate. ”

“ If the printing is to be done on a hand press, a lithographic leather roller is charged with printer's ink, and the plate, which has been fastened on a suitable bed-plate in the press, is rolled up while it is still moist. ”

“ There is the opportunity to play with, and work hard over, a plate. Perhaps the etcher has not, for reasons only known to himself, put in the plate all that can be shown in the print by ordinary printing. The printer actually has to interpret in his printing the etcher's meaning, for the which, as a rule, he gets "more kicks than ha'pence," and in the end wishes he had stuck to plain plate printing as far as the profit is concerned.
In the process of printing an etching, the printer first covers the plate with ink and then wipes it with the rags, and, if necessary, with the hand. ”

“ The printing paper does not come in contact with the plate before the instant of printing or remain upon it after the operation, but is held to the cylinder by the grippers and mask, and so carried over the inked plate, consequently little opportunity is afforded for absorption of the etching fluid. With chalk paper and a new plate damping may be necessary every twenty-five impressions, but as the plate becomes older fifty or even one hundred may be printed between the etchings. On plain paper of hard surface much longer numbers may be expected. ”

“ The art of printing, in all its numerous departments, is essentially an art of copying. Under its two great divisions, printing from hollow lines, as in copperplate, and printing from surface, as in block printing, are comprised numerous arts.
84. Copperplate printing. In this instance, the copies are made by transferring to paper, by means of pressure, a thick ink, from the hollows and lines cut in the copper. An artist will sometimes exhaust the labour of one or two years upon engraving a plate, which will not, in some cases furnish above five hundred copies in a state of perfection. ”

“ The plate, having been etched as deep as is safe, is then turned over to the router, whose business it is to cut out all the metal between ornaments and lettering to the proper depth. This done, the engraver, who in former years practically dug out the entire plate with his hand tools, comes in to give the finishing touches and correct any slight imperfection that may remain. It is of the utmost importance, of course, that the dies should be clear-cut and deep, to avoid clogging up in printing, particularly in the plates used for stamping (p. 223) in inks. ”

“ Here the half-tone process ends, the resulting plate being produced by any of the photo-engraving methods; but the most satisfactory results are obtained by photo-etching. The main objection to the half-tone plates is their lack of relief. No great depth can be obtained without sacrificing the effect. In printing these plates the greatest care in making ready must be exercised, and a smooth surface paper must be used. It is also necessary that a fine grade of ink be used in small quantity, and that it should be properly distributed. ”

“ They use a flat-bed press. For this reason it is necessary that the advertising-plate or dealers cut which you furnish to them should be mounted type-high.
The best plate you can furnish them is none too good; their make-ready and the general handling of their material is not of the highest order in efficiency as compared to the large dailies, and it is entirely probable that even with a good sharp electrotype, your advertisement may not show to advantage. With a stereotype, the liability of smudgy printing is greatly enhanced. ”

“ There are, however, certain differences between plate-printing and block-printing which affect the essentials of art. When paper is driven into a line so as to fetch the ink out of it, the line may be of unimaginable fineness, it will print all the same; but when the paper is only pressed upon a raised line, the line must have some appreciable thickness; the wood engraving, therefore, can never—except in a tour de force—be so delicate as plate engraving. Again, not only does plate-printing excel block-printing in delicacy; it excels it also in force and depth. ”

“ Sheets of thin tissue paper, pasted together and backed with damp unsized thicker paper, constitute the mold or matrix for the papier-maché process. They are firmly and evenly impressed on the page of type, which may be flat or curved, and are then dried upon the page. When dry the matrix is removed, and adjusted to an iron mold on which melted type metal is poured from several openings. The plate so made is then cooled, planed, and beveled to fit the press. All the operations, aided by machinery, are made with great speed. Ten minutes is the ordinary time. ”

“ As each color is placed, the plate is wiped clean with rags as already described, and when all the colors have been properly placed, the plate is pulled through the press in the same manner as in ordinary printing.
The successful printer of color plates must be a rare artist or else work under the direction of an artist. Little of this work is now done except in Paris and Vienna, and the limited number of color plates of this kind used for book illustration in this country does not warrant the time and expense necessary to train printers capable of doing the work. ”

“ A batch of sheets of printing paper, prepared and damped as described in Chapter V, lies between boards just beyond the block. The pad lies close to the block at the right on oily paper pinned to the table. To the right also are a dish or plate on which a little ink is spread, the printing brush (broad for the key-block) , a saucer containing fresh paste, a bowl of water, a small sponge, and a cloth. Nothing else is needed, and it is best to keep the table clear of unnecessary pots or colour bottles. ”

“ This built-up copper plate is very strong, and any number of pictures or letters—for they make moulds and plates of both—can be printed from them.
Then the editor said we should see the men printing from these plates, fastened into iron frames called "forms." So down ever so many winding stairs we travelled, until we came to a dark under-ground room, where the "Hoe" printing-presses are. ”

“ Direct Tin Printing—The Machine—Peculiarities of Impression—Cylinder Covering—Colour Sequence—Printing Inks—Drying Racks—Air Drying and Stoving.
“Direct tin printing” is not, as the term might suggest, a direct impression of the printing forme on the metal plate. It is in reality a transfer printing process in which the transferring medium is a cylinder with an elastic covering. ”

“ The slenderness of the incised lines, the fineness and hardness of the metal, and the peculiar method by which the ink is laid on the plate and fixed to the paper, give to prints from engravings on steel or p020 on copper a sharpness of line, a brilliancy of color, a delicacy of tone, and a receding in perspective, which have always won for this branch of printing the preference of artists. Yet it is a slow and expensive process. A steel-plate engraver may be engaged for many months upon a large plate, from which but forty perfect impressions can be taken in a day. ”

“ Plate-printing gives by far the finer and sharper impression, but as there is a perceptible body of ink transferred to the paper from the cut lines, it has been supposed that an impression from plate would be more easily photographed than one from surface where only a film of ink is spread upon the top of the raised lines. But surface-printing being much less sharp and distinct than plate-printing, imperfect copies of notes for which that process is used are the more likely to escape detection. ”

“ When the whole of the plate has been so inked, the impression is pulled. The results are beautiful, but the process of printing is exceedingly slow—three or four impressions a day, only, being obtainable from a moderate sized plate. ”

“ The corrector takes a sharp tool, and punches a hole through the plate where the interloper is, just the size of the type, and then restoring a common type e, through the opening, cuts it off even at the back of the plate, and solders it in its place with lead. In this way a whole line of type is sometimes introduced for an incorrect line in the plate. The corrections being made, the plate is ready for the press. When not in use, the plates, being very valuable, are carefully put in a box,—a large book requiring several boxes. ”

“ Prints produced by the third method, copper-plate printing, give far greater difficulties to the photo-mechanical worker. Every pull from the engraved plate—etching scraper drawing and photogravure excepted—possesses a tone on its surface, which is, moreover, very unequal, and although increasing its artistic qualities, offers, however, considerable difficulties for reproduction. ”

“ They are very sensitive to water and are regarded as one of the best preventatives of the cleaning of used stamps. Beautiful results are obtained by printing stamps in two colors. Of course, this necessitates the use of two plates for each design. This also gives rise to some interesting varieties, caused by one part of the design being printed upside down. Such oddities are scarce and are highly valued by philatelists.
When a plate is to be printed from, it is first warmed, then the ink is applied and rubbed into the lines with a pad. ”

“ The matrix is rapidly dried on heating surfaces, and then accurately adjusted in a casting machine curved to the exact circumference of the main drum of the printing press, and fitted with a terra-cotta top to secure a casting of uniform thickness. On pouring stereotype metal into this mould, a curved plate was obtained, which, after undergoing a certain amount of trimming at two machines, could be taken to press and set to work within twenty-five minutes from the time at which the process began. ”

“ It has not been much improved since its invention. Steel plates may be duplicated by means of electrotyping, or by the process of transfer to soft steel, but these duplicates cannot be made so cheaply as typographic stereotype plates, nor so promptly as transfers by lithography. The inking and cleansing of the plate, always dirty and disagreeable work, has hitherto been done only by hand. All the manipulations of copper-plate work are slow and difficult: they present many obstacles to the use of labor-saving machinery. ”

“ Commercial plate glass varies in thickness from one-fourth to three eighths of an inch, and the thicker plates are rather rare. A large plate of it is easily broken by a slight uniformly distributed pressure. But the pressure that is required for the blue process printing, although slight, is much greater than is used in the ordinary photographic process. For the sensitized paper that is used in the blue process printing is, comparatively, very thick and stiff, and it may cockle more or less, while the paper that is used in ordinary photography is thin and does not cockle. ”

“ It is the printing that makes its use expensive, rather than the making of the plates; and as each plate must be printed separately and on special paper, it cannot be employed with type, like relief blocks.
There is much uncertainty about the production of plates by the photogravure method; and although great improvements have been made in the process, it is often necessary to produce several plates before a satisfactory one is obtained. In all these reproductive processes the more artistic the workman the better the result ”

“ The ink is allowed to ooze out generously on to a large metal cylinder, where it is pounced upon at once by a cohort of gelatine rollers and pounded and smeared in various directions and ultimately taken by carrying rollers with reciprocating motion to larger gelatine cylinders, which are in contact with the plate-carrying cylinder itself. All this pounding, squeezing and manœuvring are the only means of getting an absolutely even distribution of ink, which the reckless speed of newspaper printing requires. ”

“ After leaving the etching room the plate goes to the "router," an ingenious machine, with a cutting tool revolving at a speed of fourteen thousand revolutions a minute, which quickly removes (p. 169) the waste metal in the large open places between the lines and dots. The zinc plates are carefully looked over by a finisher, defects are removed, and the metal plates are then nailed on wooden blocks, so that they will be "type-high," that is, of exactly the same height as the metal type-forms used in printing. ”