The difference between spot color printing and four-color printing in English Storybook

The difference between spot color printing and four-color printing in English Storybook

Spot color printing refers to the printing process of using inks other than yellow, magenta, cyan and black to reproduce the color of the original manuscript. In packaging printing, spot color printing is often used to print large area background color.

Questions about spot color printing

1. What kind of products will use spot color printing

The cover of packaging products or books is often composed of uniform color blocks of different colors or regular gradient color blocks and text. These color blocks and text can be overprinted with four primary color inks after color separation, or can be mixed with special ink, and then only a certain special ink is printed at the same color block. In order to improve the printing quality and save the number of overprints, spot color printing is sometimes used.

2. What is the difference between spot color printing color block and four-color overprint color block in color visual effect?

The ink deployed by spot color printing is obtained according to the mixing principle of color material subtraction method. Its color brightness is low and its saturation is high: Spot color with uniform ink color is usually printed on the spot, and the amount of ink should be increased appropriately. When the thickness of the layout ink layer is large, the sensitivity of the change of ink layer thickness to the change of color will be reduced, so it is easier to get the uniform and thick printing effect of ink color.

When the color block is overprinted by the four-color printing process, because the various colors that make up the color block are mostly composed of a certain proportion of dots, the thickness of the ink layer must be strictly controlled when printing dots, which is easy to change the color intensity due to the change of the thickness of the ink layer and the change of the printing process conditions. Changes in the extent of network expansion. And that causes the color to change. And because the change of any color of the composition of the color block will lead to the change of the color block, resulting in the opportunity of ink unevenness will be multiplied, so the use of four-color printing process overprint the color block, it is not easy to obtain the uniform effect of ink. If it is not possible to overprint the color block with a multicolor machine. It is also easy to have color bias because the color of semi-finished products is not easy to control.

In addition, four-color printing is the comprehensive effect of the dot subtraction absorption and additive color mixing, color block brightness is higher, lower saturation. For light color blocks, the use of four-color printing process, due to the low coverage of ink to paper, the lack of thick ink color. Because of the Angle of the dot, it will inevitably make people feel the existence of the pattern.

3. From the perspective of improving product quality, what kind of products are suitable for spot color printing?

In the printing of large area of light and uniform color block, it is usually used to add: medium light agent to the original ink to adjust the special color ink, and then carry out field printing, so that the ink layer is thicker, it is easier to get the effect of uniform color and thick. If the four-color printing process is used, a low percentage of flat mesh must be used. However, the low percentage of flat network dot in printing is easy to be caused by tiny sand or slightly bad pumping, resulting in individual parts of dot smaller, resulting in uneven ink color: printing is easy to be due to excessive water supply in the layout. Paper powder in the printing plate and blanket accumulation, paper smoothness is low, resulting in poor ink transfer of small dot. As a result, the ink color becomes lighter and uneven.

For the dark large-area color block, the four-color printing process may need to be superimposed by several colors of high-salinity dot. The ink layer is too thick and prone to dirt on the back; The use of spot color printing process, only need to print a color, not easy to appear on the back of dirty. Using four-color printing process, some parts of text and text may be composed of several colors; The use of spot color printing process, the corresponding part of the printing only one color, to avoid the possibility of overprinting error.

4. From the perspective of economic benefit, what kind of products are suitable for spot color printing?

From the point of view of economic benefit, mainly depends on the use of spot color printing process can save the number of overprinting. Because reducing the number of overprints can not only save printing costs, but also save the cost of pre-press production.

5. Can a product use four-color printing and spot color printing at the same time?

If the picture of a product has both a color layer picture and a large area of background color, the color layer picture can be used for four-color printing, and the large area of background color can be used for spot color printing. The advantage of this is that the picture can be correctly restored by controlling the field density in the four-color printing part, and the visual effect of uniform and thick ink can be obtained by appropriately increasing the amount of ink in the background part. This method is often used in the printing and production of high-grade packaging products and stamps, but the cost of printing and plate making increases due to the increase of color number.