The Impact of Prepress Imposition on the Quality of Book Printing and Binding

Many details of the implementation of the production process were completed in the prepress imposition process, such as the unification of the rules of different jobs, the reservation of milling mouthpieces, the specification of process marks, cross-pages, and the handling of bleeding graphics. Saddle-stitched products have the following features: the inner page of the product has been crawled, the page number of the book, the brow of the book, and the heart of the edition have been unified. Imposition is a key process for implementing the production process. The consideration of whether it is comprehensive or not and whether the construction is exhaustive will affect the quality of the binding process.

1. Table paper accuracy and binding folding

Table paper is a template for manual imposition, and its drawing accuracy directly affects the page alignment, center of printing, and line of the book brow, and the accuracy of cross-page layout. The drawing of the imposition table paper should be correct, the dimensions should be accurate, and the error of the two diagonal lines should be ≤ 1mm. The Taiwan version should be drawn on relatively thick paper, protected against moisture, and checked for size before use. In principle, it should be used with the painting, and it should not be used for a long time.

2. Cross-page graphic, bleeding graphic processing

Make sure to align the upper and lower pages when composing a cross-page graphic. Make allowances for the opening, milling, and backing to avoid pressure on the graphic. Imposition reserved for milling. The mouthpiece should be physically backed with the milling back size. The mouth size is the same to ensure the accuracy of the cross-page graphic layout. The depth of the milled mouth of the bookbinding product should be designed to be 2.0~3.5mm. In practical production, taking into account the limitations of the paper format, the depth of the milling mouth can be slightly smaller in the case of guaranteeing the thorough milling of the signature. In order to be able to stick firmly on the first page of the signature, the three-handed signature is generally set to 1.5~2mm, and the four-handed signature is set to 2. O~2.5mm, the milling mouth should be enlarged when making the book block with a particularly thick product. The important part of the contents of the books and graphic texts should not be too close to the incision and should be kept at least 3mm. The bleeding texts should be additionally cut to facilitate cutting.

3. Horseback booked version of the heart. Page crawling

The paper thickness and number of folds should be taken into account when making the layout. The effect of invagination of posts and posts on the page number, saddle-stitched products must do the corresponding creeping processing on the internal version of the page and the page number. For example, when printing a 16-page, 3-print sheet product with 70 g/m paper and processing it in units of a whole frame, the general second-page version of the heart and page number should be moved outward by 1 mm in the direction of the opening, and the third version should be moved outward by 2 mm. For the 8-page set of 8 pages of the lock line products and similar WD-B type book offset presses, the production of each press is a large set of 2 signatures. The 8 pages should also be considered for proper creeping processing to ensure that the internal and external signatures and layouts are aligned.

4. Process identification setting principle

The process identification should be complete and standardized, and it should be easy to print and install. It should be concise and clear. When the cover, text, and color prints are separated from each other, the rules of the heavens and the earth to be adopted shall be unified, and the signs shall be the same. There should be a difference between the two-up product and the up-and-down label. The same series of products should be distinguished in the back of the book by distinct and easily distinguishable characters so as not to be confused during binding.