The Building of a Book / A Series of Practical Articles Written by Experts in the Various Departments of Book Making and Distributing

by Unknown

Another overlay is now made in the same way as the first; only it will now be found, if the work has been properly done, that there will be only a few spots to be covered with tissue. After this overlay has been made and the necessary pieces pasted over the first one, a thin sheet of manila is smoothly and tightly drawn around the cylinder, covering completely the thick manila sheet with the pasted overlays on it. The form is then ready to print.

While the feeder, as the man who feeds the paper into the press is called, has been "filling in" the overlay, the pressman should have been getting "register,"—that is, moving the plates so that the headlines and the sides of the plates align properly, and that when both sides of the paper have been printed, the pages will exactly back each other. The ink fountain should also have been so regulated by means of thumb-screws that the right amount of ink will run on the rollers and be distributed evenly over the form. Where too much ink shows on the printed sheet, the thumb-screws on the fountain are tightened a little, to decrease the flow, and where not enough ink shows the thumb-screws are loosened to increase its flow. This process is repeated until the "color" is all right. The grippers, which seize and carry the sheets of paper through the press, the reels, cylinder bands, and many other things have also to be adjusted. These cannot well be described, but have to be learned by actual experience.

The "making ready" and watching the sheets as they come from the press to see that the "color" does not vary, is the skilful part of the process. The feeding can be done by a bright boy after a few weeks' experience, but is now done automatically by machines to a great extent.

While the press was being made ready, another set of men in charge of the paper have taken it out of the cases or bundles, counted out the number of sheets required for each form, piled it on hand trucks, keeping that required for each form separate, and have delivered it to the press. If a machine feeder is used, the paper is piled on the elevator of the feeder, from which it is automatically taken, one sheet at a time, and delivered on endless tapes to gauges on the feed board of the press, thus bringing every sheet in the same position each time. The number of sheets required for the order are printed from one form on one side and then from another form on the other side.

From the preceding it can be seen that to get a press ready may be a matter of hours, while, in the case of ordinary book work, a press generally prints from 1200 to 2000 impressions and more per hour.

The principal difference between making ready a form on a flat-bed perfecting press with two cylinders and on a single-cylinder press is in extra work necessary to obtain correct registering of the plates and in preventing an offset of the fresh ink on the second cylinder. Otherwise, a perfecting press is very much like two cylinder presses joined together. It has two sets of rollers, two ink fountains, two cylinders, two forms, etc., but only one feed board and one delivery. The sheet is fed to one cylinder and printed, taken from this cylinder by the second and printed on the second side, and delivered on the "fly board" ready to go to the shipping department.

The process of making ready forms containing illustrations is practically the same as for plain ones, except that a new underlay is made for each form, and much more care and skill must be used on the cuts themselves. It frequently happens that one or even two days are spent making ready a form of half-tone cuts, before the actual printing, which takes perhaps half a day to do, can be begun.

In most offices, a special "cut overlay" is made for forms with cuts, or illustrations. The cut is placed on a hand press before the form is made up, and proofs on four different thicknesses of paper are made. The heaviest paper is used as a bottom sheet, and the others are pasted on it. Out of the next to the thickest paper of all, the solid blacks are cut and pasted accurately on the same places on the bottom sheet. From the second or next thinner sheet, the medium shades including the solid blacks are cut and pasted on the bottom sheet, thus building up the blacks and strong shadows. From the thinnest sheet of all, the high lights and very light shades are cut, and the rest of the sheet is pasted on the bottom one. In this way the solid blacks and dark shadows on the cut have three thicknesses on the overlay; the next shades two, and the light shades one, where the high lights are cut out altogether. This is the common form of "cut overlay" used in most offices; but there are many other kinds, some being made on metal by chemical action. All kinds are fastened carefully over the impression of the cut made on the heavy manila sheet covering the cylinder, and the cut must not be moved on the form after the overlay has been fastened on the cylinder, or the effect of all the work will be entirely lost.

One of the great troubles which the printer has to contend with, is electricity in the paper. The pressman is unaware of its presence until he lifts a printed sheet from the pile and receives a slight shock, and finds the sheets stick together. In the case of a cut form, the ink is almost sure to be offset, and in printing the second side of the paper the feeder will have to stop frequently to separate the sheets. Much money has been spent and many devices originated to overcome this trouble. Ink manufacturers make a liquid preparation to be applied to the packing. A row of lighted gas-jets placed near the point where the sheet goes on to the "flyboard," a heated steam-pipe, and many other things have been used, but a new device by which electricity is generated and carried into the press, and there neutralizes the electricity in the paper, is the best of them all.

The printed sheets are counted automatically by the press, and as fast as enough accumulate, they are piled on hand trucks and removed to the shipping room. Here they are "jogged up" so that the edges are even and are counted again by hand. If they are to be shipped away, they are tied up in bundles or nailed in cases and marked for shipment. If the bindery is connected with the pressroom, they are simply jogged, counted, and piled on trucks and delivered in this way.[Back to Contents]