In the field of printing and platemaking, traditional hand-stabs and impositions are heavy and inefficient, and there is a great deal of duplication of effort. The computer imposition technique makes the work of imposition large and easy. Its convenience has completely changed the traditional way of making impositions. Automatic layout is an important part of the digital workflow. There are many layout softwares for manufacturers and software companies. It is necessary to carry out a comprehensive analysis to facilitate users to choose the products that are suitable for them.

Layout features

Computer spelling, as the name implies, uses a computer to make many small pages into a printing version. The role of the imposition version in printing is to determine the most reasonable printing method, provide correct folded sheets, and also save material and shorten the printing time. We know that traditional manual imposition has high requirements for operators. Operators need to know the paper size used for printing, the type of binding, folding, bleeding, cutting size and cutting marks, crosshairs and color control strips, and creep adjustments. parameter. Now that the computer is used for imposition, the situation has greatly changed. Its main advantages are:

(1) Simplify the process flow, increase the degree of automation, replace more manual operations, and reduce the requirements for operators.

(2) Shorten production time and preparation time. Because the speed of computer imposition exceeds the speed of artificial imposition, the files that originally needed to fight one day are now completed in an hour.

(3) Reduce waste of raw materials. While reducing the setup and preparation time, the material waste during the adjustment is reduced, and the production cost is reduced. Due to the high error rate of manual imposition, it is often found that after finishing the PS version, the imposition is wrong, resulting in more material waste, and computer imposition rarely has these problems.

(4) Improve product reliability and consistency. Since the documents handed to the printing factory have been completed, the quality of the products processed at different times and regions can be kept consistent and the quality of the printed matter can be improved.

(5) Improve product quality and reduce errors. Since the imposition version was completed by a computer before the film was issued, there was no problem of registration and error, effectively improving the quality of the product.

Layout Technology

1. Fight and fight

From the main use of the computer layout, there are mainly two ways to fight and fight.
(1) Folding is mainly used for samples, books, pictures, and other printed materials that require folding, as shown in Figure 1. This imposition process is more complicated and requires the operator to have certain expertise in printing and post-press processing, such as the size and quantity of printed paper, the way of printing and folding.

(2) The freedom to fight is to save materials (film) for the purpose of imposition is relatively simple, mainly to different sizes of different files together, so that the maximum effective use of film area, as shown in Figure 2. However, it is also necessary to have a certain understanding of the printing method when printing a document on the same machine.

2. RIP pre imposition and RIP post imposition

From the point of view of the relationship between the layout and RIP, it can be divided into two ways: pre-RIP and RIP.
(1) RIP pre-imposition: First, the page is spelled into a large version and sent to RIP. This is the most common method at present. Completion of layout and trapping of each page, followed by page layout work, and production of an output file containing OPI (Open Prepress Interface) commands (for high and low resolution images when used in RIP). Finally, this document is sent to RIP for processing. However, this type of imposition makes the data volume of RIP-processed files larger, and is not suitable for transmission and reception via the network during processing. In addition, since various types of imposition software are mainly based on processing PS files, the layout software must output the prepared pages in the file format of PS or EPS before the imposition operation (DK&A's Imposition is an exception. This is a time-consuming job. At the same time, since PS files are usually much larger than the original files of the application software, they must spend more time processing files and require a large amount of hard disk storage space. Its production process is shown in Figure 3.

(2) After RIP imposition: First RIP page, then the big version, suitable for packaging, label printing. This workflow simplifies how to modify the final document. If you find that a page contains a typographical error, you only need to re-run the RIP once to correct the error and replace the original error. This is much more convenient than reusing the entire large version as a RIP. Its production process is shown in Figure 4.