Theory and practice of bookbinding / United States Government Printing Office.

  • United States. Government Printing Office.
Date:
1962
Catalogue details

Licence: Public Domain Mark

Credit: Theory and practice of bookbinding / United States Government Printing Office. Source: Wellcome Collection.

    255/260 (page 243)
    maps, plates, etc. Paper is mounted on muslin for certain purposes, such as to reinforce maps which are to be folded. A tremendous quantity of pads of all sizes are made in the Government Printing Office. Ruled forms are produced in the bindery by pen ruling or disk ruling machines. The pens for pen ruling machines are made of a strip of brass folded in a V-shape with a flat shank which clamps to a beam. More than one pen may be on the same shank. Although pen ruling machines have been in use for more than a hundred years the basic principle is still the same. Paper is fed onto a moving cloth belt or conveyor, passes under a series of pens, and is held in place against the blanket by the pressure of cords. The main advantage of the disk ruling machine is its speed. The paper can be fed from a roll, cut into sheets of the desired size, ruled, stacked, counted, and interleaved with cardboards, all automatically. On one model, the sheet can be ruled in both directions on both sides in one trip through the machine. Sometimes specifications call for rounded corners. The round- cornering machine consists of a knife and a clamp and is simple to operate. It can cut through a pile of work as high as 444 inches. Indexes of three kinds are in common use. For cut-in indexes a strip is removed from the outside margin of the page, leaving only that portion upon which the index number or letter is printed. The thumb index is a semicircular indentation cut in the page margins. The tab index consists of numbered or lettered tabs attached to and protruding beyond the margins. Sometimes page numbers are the only printing and it is uneconomical to run the work on the printing press. Work of such a nature is done in the bindery with a paging or numbering machine. The purpose of perforating a sheet of paper with holes, slots, or slits is to permit it to be torn on a predetermined line. Slits are consid- ered preferable for convenience in handling the paper after it is per- forated. Perforating may be done on printing presses or folding machines, but the bindery has special perforating machines of two kinds, rotary and vertical or flat-bed. Scoring, crimping, and slitting may be done on these machines by means of special attachments. The use of looseleaf and mechanical bindings requires that the binding edges of the leaves be punched with special punches. These are made by punching or drilling. About 50 different sizes and shapes of punches are available and special attachments will punch oblong holes and cut tabs on the edges of file cards, etc. Many kinds of mechanical bindings are available today for books of a semipermanent nature which are referred to frequently and which