Review of lithographic printability (3)

Third, the appropriateness of the replication technology

(1) Text reprint: Due to the differences in the types of manuscripts, the reflectances are not the same on the coated paper, the writing paper, or the writing brush written on burrs or other paper. Special attention must be paid to the revised exposure time when copying. Secondly, the visual results of the naked eye and the copying of the plate-making camera will also cause some differences. It will often take time and experience to do well.

(B) black and white scan over the net: As the density of the original document often can not match with the scanner, over the net must pay special attention, especially from the bright part to the dark part of the concentration and curve values ​​(or called gamma), or bright Both shades and dark-tone photographs are due to differences in the operator's technology and there are considerable differences in quality. Therefore, at the time of adjustment, it is advisable to pay attention to and compare the quality differences between manuscripts and reproductions, and it is not difficult to obtain ideal reproductions.

(3) Scanning Separation: The control of the color control and the gray balance, and the adjustment and adjustment of the optical department and the sub-optical department, all require some experience in order to do a good job. Sometimes the need to make local color corrections is a difficult operation. It takes many years and months before the operation can be handy.

(D) manual imposition: Before the imposition of the first to take into account the binding method, because of different binding methods, the number and order of imposition will also be different, while the binding, hardcover and paperback the same order, but its reserved The back distance is not the same

(5) Computer group pages: Although this type of equipment is the most recent, with the exception of a few large-scale factories, many small and medium-sized factories do not have the ability to purchase such expensive equipment. Although it is fast in operation, it cannot be modified after the film is output. Otherwise, the film must be re-launched, which will increase the production cost. Therefore, it is mostly used for making small editions in China, and it is not used to make large editions. Large editions still use hand-made imposition methods. Since this operation depends entirely on computer devices, the input, storage, editing, calculation, output, and auxiliary devices are different because of their different software functions, but the basic principles are similar.

(a) (b) (c) (d) (e) (e) (e) (e) (h) (h) (t) (eleven)