Shiny golden Inner Frame Prepress production Design basics Q&A

Shiny golden Inner Frame Prepress production Design basics Q&A

1. When making a plate, the original manuscript should be divided into green (C), magenta (M), yellow (Y) and black (K) four colors. What is the color separation principle?

A: Color drawings or color photos, the number of colors on the screen there are thousands of kinds. It is almost impossible to print all these thousands of colors in one color. Printing on the use of four-color printing method. That is, the original manuscript is decomposed into four color versions of cyan (C), magenta (M), yellow (Y) and black (K), and then the color synthesis is carried out when printing. The so-called "color separation" is based on the principle of subtractive color method, the use of red, green, blue three kinds of color filters for different wavelengths of color light has the characteristics of selective absorption, and the original manuscript is decomposed into yellow, product, green three primary colors. In the process of color separation, the color light absorbed by the color filter is the complementary light of the color filter itself, so that on the photographic film, the negative of the black and white image is formed, and then the net is added to form the dot negative, and finally the copy and the sun are printed into various colors. This is the earliest principle of color separation in photography.

Thanks to the development of printing technology, we can now separate, sample and convert the original color into digital information through pre-press scanning equipment. That is, the original color is decomposed into red (R), green (G) and blue (B) in the same way as photographic plate making, and then digitized. Then use the computer to decompose the digital information into green (C), magenta (M), yellow (Y), black (K) four color information through mathematical calculation.

2. Why should the pre-press image be screened?

Answer: Because the printing process determines that the printing can only use the dot to reproduce the continuous tone level of the original manuscript, as shown in Figure 1-2. If the picture is enlarged, it will be found that it is composed of countless dot sizes. We see that although the dot sizes are different, they all occupy the same spatial position. This is because once the original image is screened, the image is divided into countless regularly arranged dot images, that is, the continuous image information is changed into discrete dot image information. The larger the dot, the darker the color and the darker the level; The smaller the dot, the lighter the color and the brighter the hierarchy, as shown in Figure 1-3. The size of the fixed spatial position occupied by each dot is determined by the number of netting lines, for example, if the mesh number of netting is 150lpi, there are 150 netting points in the length or width of one inch. The location of the dot space and the dot size are two different concepts, for example, C50% represents the meaning that the dot size accounts for 50% of the dot space position, 100% refers to the dot size all covering the dot space position, that is, the "field" in printing, 0% because there is no dot, only the dot space position, so this place is not printed on the ink. Obviously, the larger the number of mesh, the smaller the space occupied by the dot, the more levels can be described, the more delicate. In fact, the layers and colors of the original manuscript are reproduced by this method of hanging the net.

3. What is printing color?

A: A printed color is a color composed of different percentages of C, M, Y, and K, so it is more reasonable to call it a mixed color. C, M, Y and K are the four primary colors usually used for printing. When printing the primary colors, each of the four colors has its own color plate, and the dot of this color is recorded on the color plate. These dot are generated by the halftone screen. The four color plates are combined to form the defined primary color. Adjust the size and spacing of the dots on the color plate to form other primary colors. In fact, the four printed colors on the paper are separated, but they are very close to each other, and can not be distinguished because of the limitation of our eyes. The visual impression we get is a mixture of colors, resulting in a variety of different primary colors.

Y, M, C can synthesize almost all colors, but also need black, because the black produced by Y, M, C is impure, and more pure black is needed in printing, and if Y, M, C is used to produce black, there will be too much local ink.

4. What are the equipment of color desktop publishing system? What is the software?

Answer: Color desktop publishing system is composed of three parts: image and text input part, image and text processing part and image and text output part. The specific composition of each part is as follows:

(1) Image and text input part

Equipment: scanner, digital camera, computer.
Software: Device driver software, and MAC and PC operating systems.

(2) Image and text processing

Device: Computer.
Software: 1. Computer software: Image processing software for Photoshop, Painter. 2. Graphics software are: FreeHan d, CorelDraw. 3. The typesetting software was PageMaker, QuarkXpress. 3D image production software: 3DS, Infihi-D, Strate-StudioPRO.

(3) Graphic output part

Equipment: Computer, color printer, laser printer, laser phototypesetting machine, direct plate making machine, stamping machine, direct digital printing machine.
Software: RIP, driver software, font.