Extract from The Printers' Practical Every-Day-Book by T.S.Houghton
And here it may be observed, that nothing has contributed more to improve the art of printing than composition rollers, for without them the printing machine itself would be imperfect, and the press-room, be still filled with the offensive effluvia from capping pelts. With rollers, fine work also is equally improved, for ink-cylinders, which give out the required quantity of ink with the greatest regularity and insures a proper colour, without them would be useless.
The mould, in which composition rollers are cast, being familiar to every practical printer, young and old, it is unnecessary to describe it. Few offices being without one of some description, it may suffice to observe, that that mould appears to be the best which is made in two parts and is accurately fitted and adjusted to each other with screws and flanches; the inside being turned and polished, gives an excellent face to every roller cast in it. To know the several ingredients which make the best composition is of far more consequence to those whom this little Every-Day book Is designed to assist, than to know of what material the mould is made. If the rollers be good, it is of little consequence whether the mould be made of brass, iron, or tin.
The quality of the composition, then, being the most essential, I may observe, that the proportions of the component parts which experience has tested and deems the best, is, two pounds and a half of the finest glue to six pounds of the best molasses, to which is added a half or three quarters of a pound of Paris-white, and a penny-worth of neats-foot oil. These proportions incorporated together according to the following directions, will make excellent rollers, and, with care, last several months. The glue provided, break it into small pieces and put it to soak for about six or eight hours in the bottoms of ale. This is much better than water, as its tendency is to promote the adhesive quality of the glue. This being done, put the glue into a sieve to drain for a short time, after which put it into the melting-pan, (which, I need hardly say, is like a glue kettle) and place it on the fire. When it is perfectly melted, add the treacle, and let them boil together and be well stirred for about three hours. Adding, then, the Paris-white (which should previously be made as fine as possible,) in small quantities, it will be necessary to keep stirring the composition until all be thoroughly incorporated, which may take, perhaps, about hour. It will be then ready to pour into the mould. As it is necessary to oil the inside and prepare the mould before pouring the composition, this must be done, and the mould placed before the fire to warm while the composition is boiling. The mould being warmed, pour the composition slow, the better to expel the air and avoid the holes consequent on it being confined, and let it stand till it is perfectly cold. The best way to cut the superfluous composition from the ends, after taking the roller out of the mould, is to encircle them with a piece of thin cord, and pull each end till it cuts through the composition. Hang it up out of the sun till the following day, when it will be fit for use.
As composition balls are used for small jobs more from choice than necessity, it can only be necessary to observe, that the same proportions will make balls equally as good as rollers. Those who choose balls for small formes will know well enough how to make them, while those who do not know will neither know their loss nor be likely to inquire. Whether the forme be large or small, with a good roller, there will be no difficulty in working it. Hence my reason for deeming further notice of balls unnecessary.
In re-casting rollers, it is necessary at all times to add fresh ingredients, but in what proportions must, of course, depend upon the state of the roller requiring it. This necessity arises from the quality of the composition being materially deteriorated by frequent meltings. If, then, the roller be too hard, more treacle and a little less glue may be added to the old; if too soft, a little more glue may be all that is necessary;—but if right when re-cast, let the proportions be half the quantity of that given for new rollers. In any instance, however, a little Paris-white should not be omitted, as it is that which binds the whole together.
When rollers, in working, show an appearance of grease and make friars, a mixture of spirits of turpentine and water, or a little pearl ash lye, will greatly improve them. If they be too soft, once washing in spirits of turpentine will harden them.
The rollers being prepared, let the ink-table be next washed, that it may be dry before the forme is ready for press. For no forme can reasonably be expected to work well with an ink-table on which there is dirty ink and dust.
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