Inkjet files are usually very large. If the big screen still uses the resolution of printing, the computer can't stand it at all, so it's unnecessary. It is necessary to understand the truth that "I don't know the true face of Lushan Mountain, but I am only in this mountain". For example, Photoshop can't make more than 30 thousand pixels. However, there is no dead standard for inkjet resolution. The following resolutions are used when making inkjet images of different sizes, for example (the image area is square meters, and drawings can be made according to the following requirements):
More than 400 square meters (resolution:10.16 dpi) 4 pixel/cm;
200-400 square meters (resolution: 12.7 dpi)5 pixels/cm;
120-200m2 (resolution:15.24dpi) 6pixel/cm;
80- 100 m2 (resolution:17.78 dpi) 7pixel/cm;
60-80m2 (resolution: 20.32 dpi)8 pixel/cm；;
30-60m2 (resolution: 22.86 dpi) 9 pixel/cm;
20-30m2 (resolution: 30.48 dpi) 12 pixel/cm;
20 square meters or less (resolution: 38. 1dpi or more)15pixel/cm;
Note: When it affects image stitching, we need to cut the file. When the pixel/inch unit is an integer, there will be errors, but when the pixel/centimeter unit is an integer, it will be very accurate because we are perfectionists.
The photo resolution is usually 72dpi. If the file is too large (for example, in the Photoshop menu, the file size exceeds 400 megabytes when the image/image size shows the actual size), you can appropriately reduce the resolution and control the file within 400 megabytes.
Storage format requirements:
It is best to store inkjet and photo images in. Tif format, LZW compression format is a good idea. It can not only reduce the space and save the file transmission bandwidth, but also have no quality damage to the picture at all.
Please note when exporting CorelDRAW:
When CorelDRAW software exports bitmap, it should not exceed 10000 pixels, otherwise the image will be squashed. At this time, it is necessary to cut the map. One piece can't exceed 10000pixel, only three pieces are needed at most. Photoshop cannot process the file because it exceeds 30000 pixels.
Illustrator exports comments:
Illustrator combined with Photoshop is perfect, but after the file is enlarged, sometimes there will be some low-level errors, which need attention.
Color mode requirements:
Ink-jet printing uses CMYK mode uniformly, and RGB mode is prohibited. At present, all the modes supported by inkjet printers are CMYK mode, but if you draw in RGB mode and then switch to CMYK mode, the color will change, most obviously yellow. After changing the yellow of RGB mode to CMYK mode, the yellow will be cyan, so the sprayed yellow will turn green, and other colors will also change, because the imaging principle of ink and display screen is completely different, which determines that RGB mode can not be fully displayed in CMYK mode. Therefore, ink-jet printing and photographing should try to adopt CMYK mode. Therefore, when drawing, we should follow the CMYK standard. Photos should also be in CMYK mode. And if you want to have special requirements for color (such as standard color, etc. ), you need to provide a color draft, adjust the color of the picture, close to the sample.
Requirements for black parts:
Monochrome black (C=0 M=0 Y=0 K= 100) is strictly prohibited for inkjet printing and photographing, and four-color black must be composed of C, M, Y and K. ..
For example, Photoshop defaults to black (C=75 M=68 Y=67 K=90), otherwise the black part of the inkjet screen will have horizontal stripes, and the monochrome black will turn gray, which will affect the overall effect. If some files appear monochrome black, how to solve it?
First, you can convert files in CMYK mode into RGB mode first, and then into CMYK mode. The premise is that monochrome black must meet the condition of K= 100;
Second, you can use the selection tool to fill the default black directly after selection;
Third, under the Photoshop menu, choose a color for image/adjustment/selective color to adjust black.