1. Determine the picture accuracy to 300dpi/pixel/inch.
2, determine the picture mode is CMYK mode
3, determine the real bottom (such as pure yellow, pure black, etc.) no other noise
4, the file is preferably an unmerged layer PSD file format
5, the text description in the picture is best not to complete in Photoshop, because once converted to the image format, the word will become hair.
Photoshop jobs generally only contain image categories. If you are making a printed page, it is best to use different software for image, graphics and text.
For the delivery of printed images, the most important thing is to pay attention to the resolution of the image and the size of the image; the general formula is: resolution = number of screen lines × (1.5-2). Followed by the problem of color mode; the color mode of color images, to use the CMYK form.
Black and white images, if not required, are generally grayscale. For a line image such as a bar code which must be expressed in the form of a dot matrix image, the general resolution is not lower than 1200 dpi, and the color mode is a binary map (Bitmap). Furthermore, dot matching is also an important issue affecting image quality.
For CMYK dot matching of contrast, dot size and gray balance data, it must match the post-printing process.
For example, if printing on offset paper, the dot contrast is generally between 5% and 85%; if it is coated paper, the dot contrast is between 2% and 98%.