There are quite a number of processes that have been brought into use with more or less success, as Graphotype, Dallas-type, etc., to which it is not necessary to refer, as for all practical purposes Zinc Etching holds the field against all others, either for Half-tone Blocks, or for Line-Blocks of every kind, of which last a number of examples are here given, with an explanatory title to each specimen.
For work of the very finest kind, the Photogravure or Heliogravure, printed by the copper-plate press, bears the palm, but it has the disadvantage of being very expensive. Those desirous of knowing more fully concerning the various processes in use may be referred to a very excellent volume in the “Book Lovers’ Library”—“Modern Methods of Illustrating Books,” by H. Trueman Wood, M.A., Secretary to the Society of Arts, and published by Elliot Stock.
These modern methods provide a most important and valuable means of producing illustrations for printing purposes. By their aid, any photograph, drawing, design, or engraving of any kind can be translated into a block, and with such success that, with suitable subjects, it is often hardly possible to tell the original from the copy; and not only do they enable surface blocks to be produced with great rapidity and at slight cost, but they give blocks capable of producing effects which could not be obtained at all by wood engravings, or, if at all, only at great expense.
Many artists have hailed with delight the process of Zinc Etching, as by its means they obtain a perfect fac-simile of their work, more especially pen and ink drawing, which could never be reproduced by any other method with the same accuracy and delicacy of finish which the zinc process gives, and which could not by wood engraving be an absolute fac-simile.
Mr. Carl Hentschel, head of an eminent firm of photo-etchers, to whom we applied for information upon certain points in the manipulation of his process, courteously offered some very interesting statements as to the development of zinc etching. He says the process of Zinc Engraving was introduced into England about thirty years ago, but really did not “catch on,” as the Yankees would say, for twenty years after; nor was there any real value attached to it from a commercial point of view until about twelve years ago, when, as Mr. Hentschel assures us, the system he adopted rendered it possible to have blocks of all kinds for newspapers, books, magazines, and journals of every description produced in such time that their delivery could be relied upon for the most urgent publication, and, only then, the vast possibilities of the zinc process began to dawn upon publishers, and soon the method was gradually adopted for all purposes of engraving. Some idea of the extent to which it is made use of may be gathered from the fact that this firm alone delivers weekly about three thousand blocks for various publications throughout the country, and even to far-off India, where the plates of whole volumes of educational works have been despatched by this enterprising firm. To keep pace with the requirements of the times it has been found necessary recently to add largely to the facilities for the execution of half-tone blocks, using engine power to the extent of forty horse for the production of the electric light, essential for this branch of the business, so that in this respect they are practically independent of sunlight. In cases of emergency it is no unusual thing to deliver half-tone blocks in five to seven hours, and Line work, from transfers, one and half hours, and in the case of having to photo the subject, two and half to three hours. This would have been impossible under the old system, trusting to daylight, and this fact, coupled with the cheaper rate of cost, has given an impetus to illustrated journalism that could hardly have been dreamt of under the old regime.
Under the head of photo-lithography, the initiatory stage in the making of what are termed “Process Blocks” was explained, namely, the making of photo-transfer from the original drawing—in printer’s ink—for transference to the lithographic stone and printed form. The metal Zinc possesses the same or similar properties as lithographic stone, and may be used to print from in the same way. The term Zincography is applied to the process, though practically it is the same as lithography.
To convert the design upon the zinc plate into a relief block to print with type is only one step farther—to so protect the lines of the design on the zinc plate, as to resist the corrosive action of acid, and by etching the plate, produce a relief block. For this purpose, a resinous or bituminous substance is introduced into the composition of the printing ink. Here, then, we have the lines of the design in an acid-resisting material upon the surface of a metal plate exceedingly susceptible to the action of acids. If the prepared plate is now placed in an acid bath, the entire surface of the zinc, except the protected lines, will become etched, or dissolved away, leaving the design in its integrity, with the lines standing up in relief: the etched plate has now only to be mounted upon wood to the height of type to be ready for the printer’s use.
Such is a brief outline of the process in the production of Line Blocks. The design may be put on the metal plate in any of the following ways:—
The most perfect work is said to be obtained by the latter method. There are many technical difficulties to be encountered in working the process, difficulties which for twenty years kept it at the experimental stage, and of little practical utility, as, for instance, after etching the plate for a short time the acid has a tendency to bite laterally as well as vertically, and so undermine and weaken the lines intended to be left standing. This is obviated by some photo etchers in using certain chemicals, and others by an ingenious manner in the working by etching in stages. This is done by re-inking and dusting with bitumen, heating the plate after each “etching,” which has the effect of melting and spreading the resinous or bituminous ink on the face, and slightly down the sides of the lines. Successful work is only attained by attention to the various delicate technical manipulations, which only experience can give.
The subject, whether it is a drawing, engraving, painting, or a photo print, must in each case be photographed to obtain upon the negative the texture which is the means of producing the gradations of light and dark we find in the finished block. The theory is simple enough, but the practice is extremely difficult, and one requiring great skill and care. A glass screen having cross lines ruled upon it, with perfect mechanical regularity (about seventy lines to the inch for large work, up to two hundred lines to the inch for very fine half-tone blocks, as may be best suited to the subject in hand). The screen is fixed in the camera between the lens and the negative to be exposed. The fine black lines of the screen are reproduced upon the negative as white lines, breaking up the picture into a series of minute square dots, of varying size according to the light and shade of the original picture. A photo-transfer is then taken as previously explained. (In Hentschel’s process the secret of the prepared transfer paper is in the possession of Mr. Hentschel solely.) After being transferred to the zinc, and manipulated with certain chemicals, the plate is gradually etched until a sufficient depth has been obtained. It is then trimmed and mounted type height ready for the printer.
Drawings for reproduction by the modern processes of photo-lithography and photo-etching may be prepared in a variety of ways. The most frequently used is termed Pen and Ink Drawing (often mistakenly called “etching,” which is engraving by means of an acid). This class of work is the most popular of all, and the most easily got at by artists and amateurs; it is translated with much greater ease, and at less cost, than photographs or shaded drawings of any kind. As the term indicates, it is executed with the pen; many artists, however, have a predilection for the brush (a fine sable pencil), which, though it requires considerable practice to master its use, becomes in masterly hands a valuable instrument, capable of greater and more varied effects than the pen. Good black ink, and smooth white paper or cardboard, are the essentials. Much may be said on the style or modes of different artists in drawing, the kind or quality of the ink, the pens and paper to be used. The relative values of thick and thin, open and close lines, the direction of the lines, etc., in producing the varied character and quality of good expressive drawing; the various textures of surfaces—roughness, smoothness, etc.—have all to be considered, more especially if the drawing is made upon a larger scale, to be reduced in the photo-etching process of translation. We heartily commend the shilling handbook on Pen and Ink drawing published by Winsor and Newton. It is an excellent introduction to the art; it gives full instructions on the best means of working, and the materials to be used.[3]
For Half-tone Shaded Blocks the design may be executed in washes as a china ink drawing, or in any other way. The illustrations are reproductions from various kinds of originals, as explained under each example.
Messrs. Carl Hentschel & Co., 182-3 Fleet Street, have been good enough to prepare several examples to illustrate the half-tone process; each block having been made from an original executed in a different way, as indicated by the explanatory title; and may be considered rather severe tests of what the process is capable. For these favours we are much obliged; we tender also our thanks for their kindness and courtesy in supplying much of the foregoing information.