Folding method of imposition process (middle)

If it is a 16-page magazine cover, it can be converted into a self-reversed version in the following manner. The typesetting method is shown in Figure 3-4.

Figure 3-4 Schematic diagram of the self-turnover version and its layout

If it is four fold, it can be made into different layouts depending on the paper. For example, as shown in Figure 3-5, a fan-folded booklet with a size of 100 x 185 x 4 fold is used. When a 787 x 1092 (mm) paper is used and four open pages are used for printing, the typesetting method is applied as shown in the figure. Rolling version shown in 3-6. In this way, when the printing is turned over, it is necessary to exchange the mouthpiece. Therefore, when printing a high-precision printing product, there is a high requirement for printing equipment and paper.

Figure 3-5 Schematic diagram of sector folding and layout

Figure 3-6 Schematic diagram of imposition

2. Imposition of books

Books (magazines, albums, atlases, etc.) must first understand the format, number of pages, and binding method (book saddle stitching, wire binding, sewing thread or glue binding), and printing color of pre-print imposition before printing. The number of elements (monochrome, bi-color, or four-color), the thickness of the paper, and the form of folding (hand-folding or machine folding), etc., can be used to determine the method of imposition.

Choosing the right way of imposition can not only make the imposition binding smooth, but also save costs and improve the quality of books and magazines. In the printing process, the layout of the pages is subject to specific rules. Regardless of the number of pages, it must be arranged in a specific layout in accordance with the law in order to print. That is, the number of folding (F) and the number of pages (L) and the number of pages (A) and the number of printed sheets (I) have a certain rule, that is, the first folding forms two pages of four pages, and the second folding forms four pages of eight pages. Page number ..., the relationship between the discounts and the number of pages and the layout is shown in Table 4-1.

Table 3-1 Relationship between Discounts and Pages and Layout

It can be expressed as a formula:
L = I×2F
A = 2L = I×2F+1