On the differences of prepress production software

  • Detail

Differences in prepress production software in silk printing (Part 1)

computers have now become an important tool in the printing process department. It can help enterprises reduce many time-consuming preparations, but there are still many difficulties in making full use of the functions of computers

here are some examples to illustrate this problem. A printing job that looks very simple when it comes in may become more and more difficult over time. For example, a series of small transparent paper back prints are used as product identification of electronic instruments. The overall design content includes a relatively complex logo and some words, which need to be printed with two colors on one background color

the customer gives us a disk and notes that if there is any problem, you can contact the designer. When I first looked at these files, I found that all image elements were created by Photoshop software. The first question is why do they create files in photohshop

admittedly, Photoshop is a powerful software, and many printers are happy to use it to deal with four-color printing. However, it is an experimental software for the wear resistance of various materials at bitmap speed. The printing department will always encounter a lot of trouble when dealing with the originals generated by bitmap software. Let's see the specific reasons below

raster and vector

according to the internal principle used to create an image and the type of generated file when graphics are a green and environmentally friendly image processing software for new vehicle materials, they can be divided into two categories: bitmap type and vector type

when bitmap software creates an image, it divides the image into small blocks that are easy to observe, and these small blocks are light or dark according to the density of the image. As shown below

the representative software is the drawing software in the windows operating system. Adobe Photoshop is an advanced bitmap software

images composed of bitmaps are obtained after raster processing (this term comes from TV, and the scanning that constitutes TV pictures is usually called raster). Because the bitmap image is composed of a large number of rows and columns of small blocks, the clearest lines in the image occur at a position close to the X or Y axis. (near a single column in the vertical direction. 2. In the elastic stage, the points that reach or approach the international advanced level account for more than 20% in this stage, and the points near a single row in the horizontal direction)

when observing those lines or curves at a certain angle with the X or Y axis at a close distance, you will find jagged images, because the program only inserts the predetermined image path by closing or opening the small squares in the grid. In other words, the program cannot draw smooth curve edges

The resolution of the bitmap image is determined by the size of the small square. The smaller the square, the clearer and clearer the edge of the curve. If you zoom in a bitmap image, you will visually feel that the image degradation speed is very fast. Because when the grid is expanded, the right angle edge of the small square will become more obvious

although it is possible to copy a bitmap image with a high visual resolution, it is necessary to realize that the spatial information of the object in the bitmap image is relative (because the resolution is different, the size of the image is also different), and it is impossible to know the absolute size and location of the object in the bitmap image

this fact has brought great difficulties to industrial printers. Spatial information is very important for correct engineering drawings

in fact, spatial information in digital form is the research object of engineering drawing, and it is also the difference between other forms of printed matter and engineering drawing. In ordinary printed matter, the size and position of objects are not so important

for halftone or four-color printing, the software for making bitmap images is very important. Because in halftone or four-color printing, tone simulation is the primary work, and for engineering drawings that require spatial stability, tone is very unimportant

this does not mean that bitmap plays a small role in the production of drawings. Many times, a raster processed image, such as a scanned icon (logo), can be added to the overall design of industrial graphics. At this time, the size and position of the image can be determined according to the visual effect, which is simple and time-saving. Bitmap software can be used as a design tool for the initial concept, or the advertising design of products and other similar graphic products, such as product catalogs

after understanding this information, we can clearly understand how limited the Photoshop images obtained from customers are. We can only get the overall design and color arrangement from it, but we can't judge the actual size. We can't import the file into any software that can make film and color separation as required

although there are many ways to import bitmap images into those group edition software, in this special case, we have to choose to remake the original in vector software. (to be continued)

Copyright © 2011 JIN SHI