Color printing is a way to copy image or text in color, but it is not easy to improve the quality of color printing.

Perhaps you have heard many complaints from art editors and photographers about the poor quality of color printing in today's pictorials, photo albums and periodicals, the inability to restore the original, the serious distortion of color, some of the colors have become pattern color blocks, some of the light and shade, the reversal of levels, and even some of the production processes before printing and brushing have seriously biased the colors of the characters and landscapes on the manuscript In addition to the poor quality of the original, most of them are caused by improper scanning and color separation technology. There are three kinds of improper color separation techniques,

First, the production process before printing uses a low-grade platform scanner (about 20%) so that the quality of scanning and color separation is poor;

Secondly, due to the lack of concept and standardized operation method of reducing scanning and color separation, the advanced technology and powerful functions of high-end professional scanners and electric extension high-end networking have not been fully developed only by subjective adjustment based on different screen colors;

Third, the operators lack the aesthetic level and the ability to analyze the original drawings correctly, and can not set the correct parameters and adjust the most reasonable according to the characteristics of various originals. In addition, there are also a few customers who are not knowledgeable but blindly command.

It has been proved by practice that the scanning and color separation technology of color image reproduction and printing is the key to the quality, because on the one hand, the current computer plate making needs to input the simulated color image, reversal film and other image art, first of all, it needs to be scanned into digital image, and then it can be transferred in the digital process of prepress system. In this scanning and conversion process, there are two key technologies Skills need to be mastered,

One is how to apply the scanner (get the best color level information from the original at the beginning of scanning);

Second, the image file input from the scanner is usually RGB format. Before outputting the color divider, the file needs to be converted into CMYK format, that is, the conversion of color space. This step can be said to be the key of color separation processing. According to the printing suitability of ink and paper, it is necessary to set the parameters of dot enlargement value and gray balance, and to select GCR or UCR color separation mode. Only by setting these parameters correctly, it is possible to output high-quality color separations.

On the other hand, scanning color separation is both technical and artistic. According to different types of originals, it is necessary to set and adjust the parameters of gray balance, gradient contrast, color correction and clarity in terms of technology, and to deal with the relations of color tone, saturation, space distance, light and shade, light and shadow change in terms of aesthetics. It can be said that the level of these two aspects of operating technicians will have a great impact on product quality. Therefore, in order to achieve high-quality color printing, we must fully grasp the key technology of scanning and color separation, and improve the operation and technical level of operators.