Print knowledge summary 8B
Second, graphics, image processing and group edition
We are a big printing company in Shenzhen China . We offer all book publications, color advertising pictures, hardcover album, packaging box, calendars, all kinds of PVC, product brochures, notes, Children's book, stickers, all kinds of special paper color printing products, game cardand so on.
For more information please visit
http://www.joyful-printing.com. ENG only
http://www.joyful-printing.net
http://www.joyful-printing.org
email: 860681365@qq.com
1. Setting of color separation parameters
This mainly includes printing ink settings and separation settings.
(1) Setting of printing ink
1 If coated paper is used for printing, the ink may be TOYO INKS or SWOP INKS. Other parameters can be based on specific paper.
2 dot gain refers to the expansion of outlets at 50% of the midtones. If printing on coated paper, it is recommended to take between 12% and 15%; if printing on offset paper, use 15% to 20%; if printing on newsprint, it is 20% to 25%. The larger the value is set, the smaller the CMYK data after color separation.
3 Gray balance refers to the value of ink gray balance at the time of printing. This value is available for every printing factory.
4 Grayscale images use dot gain. By clicking this item, the grayscale image will change based on the dot gain compensation. The larger the dot gain value, the darker the display. The give option will also affect the conversion data of other modes to grayscale mode. For example, when you convert a grayscale image from RGB, select this item and the software will automatically invoke the dot gain value to compensate the grayscale value. The larger the dot gain value, the smaller the gray scale data.
(2) Separation settings
Select the separation set up option under file/preference.
1 Select Separation Type There are two color separation types, GCR and UCR. You can choose one at a time. GCR is a gray component replacement; UCR is a background color removal. The background color removal here is different from the background color removal on the previous electric extension, so it is recommended to use the GCR mode.
2 determine the black version of the tone curve (black generation) when the gray content of the image is not very much (such as landscape pictures, portraits, etc.), usually set the black version of the tone of the black version; if the image is high saturation, High-contrast art photography can be used as a black version with a short tone and high contrast; when there are many gray components in the image (such as old paintings), the long version of the black version is used.
3 black limit The different types of manuscripts should have different values, from 70% to 90%, usually 85%.
(4) The total ink limit (tital ink limit) indicates the maximum value of the sum of four color dots. For example, off-press offset printing takes 340% to 380%; newsprint is about 260%.
5 UCA Amount This value mainly increases the value of CMY at the dark tone. This value can be larger for dark manuscripts, such as 40%; otherwise, the smaller the better.
2. Color correction
Photoshop scans the output of the picture mainly from two aspects of processing: the full-color correction and selective teaching is. For full-color correction, the curves can be used to correct high and dark tone values, taking into account the tone and gray balance of the image; for selective color correction, the local color blocks in the figure can be adjusted as necessary. The amount of adjustment can not be too large, otherwise it is easy to produce hierarchical faults.
After the graphic image is processed, the groupware can be used to create a version. After the group version, the output can be output, that is, the film can be prepared.
点击图标下载 App