The Development of the Printing Press
( Originally Published 1930 )
When the art of printing with movable or separate pieces of type was invented, not much attention was paid to the presses. The earliest printing presses were crude mechanical devices, made of wood and modeled after the cheese and the wine presses which were in use during the Middle Ages. Each of these consisted of a bed upon which the form of type was placed, and of a platen or wooden block. The paper was placed over the form, which consisted of a wooden frame and the type that it held together, and the platen was screwed down over it so that the paper was squeezed against the type, thus printing only one sheet of paper at a time. After one sheet was printed, the platen was unscrewed, the sheet removed, another sheet placed on the form, and the process of pressing repeated.
Since those early days, many changes have been made in the printing press and many new devices have been developed for the purpose of putting on paper the composed matter that has been prepared in the composing-room. The construction of the press out of iron was one of the first. changes that was made, and, along with this development, a number of mechanical devices were introduced which made it easier to operate this machine. Improvements were made from time to time, and new types of presses were invented until, today, we can find few, in the large cities at least, that have any resemblance to those which were used several hundred years ago.
One of the most important changes made was in the use of different kinds of power to operate the presses. Instead of operating the presses by hand power, steam power was introduced to do the work, and today, electricity usually furnishes the motive power. Furthermore, the modern devices are not operated in a pressing or squeezing manner in order to make the impression. The paper is either held up to the form or passed over it, depending upon the type of press used, with sufficient force to receive the impression of the type. A considerable amount of change was made in the form also. Today, both flat and curved forms are used. The flat forms are inclosed in a steel frame and are used on flat-bed presses, while the curved plates, which are produced by the electrotyping or the stereotyping process from flat forms, are used on the other types of presses.
As a result of many experiments, we have in use at present such general types as the platen press, the cylinder press, and the rotary press which are used in the process of relief printing or printing from raised surfaces. The platen press, which is used mainly in job-printing plants for small work, has a flat bed to hold the form of type and a flat plate, or platen, upon which the paper is placed. The impression is made when the platen which holds the paper is forced up against the bed which holds the form. The cylinder press, also, has a flat bed upon which the form is placed, but the impression is received from a cylinder which carries the paper and which turns while the bed moves back and forth under it. A rotary press has two cylinders which run at the same rate of speed. One of these cylinders carries the form which comes in the shape of a curved plate, and the paper passes over the other and thus receives the impression. Various types of each of the presses mentioned have been developed for use in different kinds of work.
Three general processes of printing have been developed in the years since this art was invented. One of these, the relief printing process will be discussed in this chapter. The other two are the planographic and the intaglio processes. In the planographic method the parts to be printed are on the same level as the face of the form, while in intaglio printing they are below the surface of the plate. Posters, labels for all kinds of purposes, wrappers for candy bars, and the like are some of the things printed by the planographic process. The fiat-bed lithographic presses, the rotary planographic presses, and the offset presses are the ones used in printing by this method. Intaglio printing is closely related to engraving. Calling cards, announcements of all sorts, and the picture supplements of newspapers, among other things, are printed by the intaglio process. The plate-printing press, the die press which is used in stamping, and the rotogravure press are the types most generally used in printing from depressed surfaces. The intaglio and the planographic methods of printing will be discussed in other chapters.