The lakes are principally formed by the use of coal-tar derivatives, and are usually incorrectly grouped as anilines. They are produced by precipitating water-soluble dyes upon a suitable substratum or base. Their shades, strength, brilliancy, permanency, and working qualities are dependent upon the nature of the dye itself, upon the nature and percentage of the substratum or base, and also upon the suitable selection and manipulation of the precipitating agents. This class of colors is to-day by far the most important of all, since through great progress made in chemistry in recent years, it is possible to make them of the greatest possible strength and permanency, together with a brilliancy of shade which was for many years an ideal earnestly striven for, but apparently impossible to accomplish.
Having thus considered the products which are the principal raw materials of printing ink, we now come to the ink itself. Being provided with all the varnishes, pigments, dryers, etc., of suitable qualities and shades, it is necessary to combine them in proper proportions, after selecting such as will be mutually compatible, and to grind them to the utmost fineness. The machinery to accomplish this purpose consists, first, of mixers, in which the ingredients are thoroughly incorporated with each other. This being done, the resulting mixture or "pulp," as it is called, is ground upon mills formed of rollers or cylinders, which are set in close contact by means of screws and made to revolve by power. Between these rollers the pulp is passed again and again, the number of times being dependent upon the consistency of the ink and the nature of the pigments, until it is ground or comminuted to the utmost fineness. The result is printing ink as it is known to the printer, varying in consistency, strength, intensity, permanency, brilliancy, drying, and other working qualities, according to the nature of the various varnishes, dryers, and pigments with which it is made.[Back to Contents]
THE PRINTER'S ROLLER
By Albert S. Burlingham
Notwithstanding the fact that no one thing connected with the art of printing has done more toward the advancement of that art than the simple inking appliance familiarly and commonly known as "the printer's roller,"—without which, indeed, the evolution of the power printing press from the primitive hand machines of the fathers would not have been possible,—it is an inexplicable truth that historians and encyclopædia makers who have made investigation of the origin and progress of the art seem to have attached so little of importance to the invention or introduction of the composition roller that only meagre and casual reference is made to it. Even its predecessor, the "ink-ball," receives but scant courtesy at the hands of these chroniclers, for while they enter into the minutest detail (and properly so) in investigating as to whom the world is indebted for the idea of movable types and the invention of the printing press, they have not thought it worth their while to rescue from oblivion the suggester or adapter or constructor—whatever he may have been—of the device by which those types were inked to receive the impression from that press, and without which neither types nor press would have been of any avail.
It seems to be established beyond doubt, however, that the first suggestion of a roller to take the place of the ink-balls in applying ink to type forms was that of William Nicholson, with whom, also, the idea of the cylinder press originated, in 1790. He recognized the fact that no power press on the cylinder principle could be of practical use without an inking apparatus different from the primitive ink-balls. These were hollowed-out blocks of beech, mounted with a handle, the cavity stuffed with wool and covered with untanned sheepskin which had been well trodden until it was soft and pliable.
The early printing presses were made of wood, and two men were required to work a press—one to make the impressions and one to ink the forms with the balls. The ink was contained in a receptacle called the ink-table. It was enclosed on three sides, and was attached firmly to one post, or cheek, of the press, on which were the racks for holding the ink-balls when not in use. A beechen implement, resembling somewhat our potato masher, and called the "brayer," was used to manipulate the ink as it lay on the table; an iron shovel, known as the "slicer," being used to portion out from the mass of ink such quantities as were needed from time to time for the brayer.
It required much strength to manipulate the ink-balls properly, and thus it was a man's work. Taking up ink with them from the table, the operator vigorously beat the balls together with a rolling movement, turning them a little at a time so as to make the ink cover the entire surface and distribute it perfectly thereon. Then the type-forms were beaten with them until they were properly inked. The work of printing off an edition was divided between the two men, one manipulating the ink-balls for an hour, and then taking his turn at the press, while for the next hour his fellow-workman attended to the inking.
William Nicholson, seeing at once that the idea of a cylinder press could never be worked out to practical perfection with such a process of inking as that, built up an inking roller with manifold layers of cloth, which he covered with the trodden sheep-pelt surface used in the ink-balls, the distribution of the ink on the roller to be made by contact with a revolving cylinder of wood. The idea was there, but that it would have had the intended result was never known, for although Nicholson's press contained nearly all the principles on which the cylinder presses of our day are constructed, it lacked one vital feature—the attaching of the type-forms to the cylinders—and was consequently not of any practical use.
The Earl of Stanhope, who, in 1798, invented the first iron frame and "platen" press, with the improvement of levers in addition to screws to give the impression, coupled with his object Nicholson's idea of an inking roller or revolving cylinder. He spent large sums in trying to find a substance that he could utilize for that purpose. He investigated with the skins of many animals, domestic and wild, and tanned and dressed in various ways. Different textures of cloth and varieties of silk were used, but without success. The seam that was necessary down the entire length of the roller was one great impediment to success, and even if that could have been overcome, the proper softness and pliability of surface for receiving and depositing the ink evenly and smoothly on the type could not be obtained from any of the processes experimented with; and Stanhope's improvement in printing presses was still subject to the inconvenience of the ancient ink-balls.
In 1807 a printer named Maxwell made a sheepskin roller which he introduced into Philadelphia. It failed of success, and the printers returned to the ink-balls. This Maxwell roller was reintroduced by Fanshaw, a New York printer, in 1815, but the printers of that city rejected it.