The material upon which stereotype plates are fixed, in order to be printed.
These risers are sometimes made of wood, with the plates screwed, or otherwise fastened upon them; sometimes of brass, bell metal, gun metal, or type metal; and occasionally of gypsum, or Roman cement: but, of whatever substance they may be formed, the riser and the plate together should be of the same height as types.
Mr. James Fergusson took out a patent for risers made of elastic substances, of which he published the following description, or specification: — “Now know ye, that I the said James Fergusson, in compliance with the said Proviso, do hereby declare, that the nature of my said Invention, and the manner in which the same is to be performed, are particularly described and ascertained by the following explanation thereof, that is to say: In the process of printing from Stereotype Plates, the plates are put upon, and fastened to, certain materials or apparatus, called by different names, such as blocks, matrix-plates, risers, &c., which are made either of iron, brass, type-metal, bell-metal, Roman cement, gypsum, wood of various kinds, or some other suitable substance; or, without using any such materials or apparatus, the plates are, or may be, put upon, and fastened to, the coffins or tables of such printing presses as are in general use, or upon cylindrical or any other sort of printing machines. In all cases, however, of printing from Stereotype Plates, it is necessary to apply some remedy to the unequal thickness of the plates; and the operation usually adopted is that of putting layers or pieces of paper, or other material, under the thinner places of the plates, or over the same, upon the tympan, which operation is technically termed underlaying and overlaying. Now, the nature or object of my Invention is that of saving the time and expence unavoidably sacrificed in the operation of underlaying and overlaying; and this object I accomplish by putting elastic substances under the Stereotype Plates, whereby the printed impressions from them are immediately equalized wholly or in part; for the elastic substances yield to the pressure upon the thicker parts of the plates, and at the same time afford the necessary resistance for obtaining sufficient strength of impressions from the thinner parts. It must be evident, that the elastic substances are to be interposed between the Stereotype Plates and whatever solid or firm substance may be made use of, whether blocks, matrix-plates, risers, cylinders, printing presses, printing machines, or any other apparatus whatsoever. So far as I have made experiments and trials of different elastic substances, I have hitherto found Cork to be the best calculated for the purposes of my Invention; but, in virtue of the Letters Patent granted unto me, I claim the exclusive right and privilege of applying Cork, and any other elastic substance, to all kinds of printing apparatus and machines, with the view of remedying the inequalities in the thickness of Stereotype Plates; and I also claim the sole right and privilege of manufacturing the elastic articles requisite for the attainment of this object, of vending such articles, and of granting Licenses for the use of the same. In further explanation of the manner in which my Invention is to be performed, it may be proper to state, that the Cork is prepared by cutting, sawing, rasping, and filing; and by these means it is wrought to such a uniform thickness as is required. I consider a quarter of an inch as a proper thickness, but a lesser or a greater may be adopted. If, when a determinate thickness has been fixed upon, the Cork is to be applied to some apparatus now in use, that apparatus should of course be diminished as much as is the thickness of the Cork, in order that the same height to paper may be preserved. The layers or beds of Cork may be formed either of single pieces, cut to the respective sizes of pages, or made up by several slips, whereby they may be adjusted to various widths and lengths. Whether the Cork be laid loose upon the blocks, &c., or be attached by soft pitch, shoemakers' wax, or other adhesive substance, is unimportant; but I prefer attaching it, so as to keep it in its place. Although my Invention essentially consists in discovering the applicability of Elastic Substances for the purpose of remedying inequalities in the thickness of Stereotype Plates, yet, in this Specification, I have necessarily given my explanations by particularising Cork, that being the material which I now manufacture and prefer. How to adapt any other elastic substance, which may answer the purpose equally well as Cork, cannot be a matter of doubt or difficulty to any person practically acquainted with apparatus used in Stereotype Press-work. — In witness whereof, &c.
Mr. T. C. Hansard took out a patent for improvements on, and additions to Printing Presses, and various processes relative to Printing; these improvements included “Stereotype-Plate Risers, with Holdfasts or Claws,” of which Mr. Hansard published the following description: — “The Risers are made of Type Metal, or with any other metal or substance, cast in a Type-founder's mould, having somewhat the form of what are called Quotations. I take the usual standard for Printer's admeasurement, and cast them quadrilateral to four Pica m's; then longer ones as parallelograms, four by eight, four by twelve, four by sixteen, and smaller ones, four by two, four by one, and four by a half; in height they are about three-fourths of an inch, or sufficient to raise the Plate to the usual height, or somewhat higher than common Type; these being cast and dressed perfectly true, in body and height, may be easily combined to form the size of any page necessary, with the certainty of having a uniform plain surface for all the plates, however numerous; they are cast as hollow cubes, the larger combinations having divisions to give sufficient support to every square against any pressure which can be brought upon them.
“The Holdfasts or Claws are formed of Brass or other hard metal, accurately adjusted in thickness to a Brevier, or any other body chosen, with a projecting Bevil at the top. They may be of various lengths, as to 4, 8, 16, 24, or more or less, Pica m's, the elongated parts of the larger ones being to the height of ordinary Reglet, having the Holdfast or Claw in the centre, or towards each end. They may be opened, or pierced, as well to make them lighter, as to cause them, by pressing and indenting into the furniture of the forme, to be less liable to be drawn out: the height of the Claw is about seven-eighths of an inch, or sufficient for the projecting bevil of about one-eighth of an inch to lay upon the flanch of the plate when resting on the Risers. To prepare plates for working, form with the Risers the requisite number of pages for the forme or sheet to the nearest size they may make by the various combinations, and add any difference wanting by reglet, leads, or scaleboard; then lay on the Plates, and place at the head, foot, and sides of each plate as many Holdfasts as may, from the size of the plate, be deemed sufficient for proper fastening; thus for small pages, as in Octadecimos and Duodecimos, one at each side and end will be sufficient; for larger pages two or more may be thought necessary; making up the parts which they may be deficient of the length and breadth of the pages with quadrats or reglet of the same body; then proceed to make margin, or dress the formes, and lock-up in the usual mode. To change the Plates; when worked, unlock the forme, draw out the Holdfast at the head or foot of the plate, slide off the done-with plate, replace by the new one; lock up again; and if the Plates have all been cast true to one gauge in thickness, width, and length, you will have throughout the whole work exact and uniform register, and equal impression; — when the Work is completed, the same material of Risers and Holdfasts, by admitting every combination of size, will form into any other sized pages for any other sized plates.”