Solve the problem before the output plate

1. General inspection method.

This method is commonly used in output centers and design companies. Its main equipment is the viewing table and density meter. Densitometer is a key equipment for testing printing plates. Its basic function is to read out the halftone percentage of the halftones, so as to judge whether the size of the halftone dot generated by the platesetter is correct. For example, at the 40% tone in the original image, whether the measured density on the printing plate is 40%. The following are the main inspection aspects of the general inspection and their meanings:

a) Test the web ladder attached to the printing plate so as to judge whether the adjustment of the printing plate is correct. It mainly examines the process of stencil printing and its parameters (such as the development speed, temperature and time, and the developer concentration, and may also include the problems of the plate making machine itself, such as the quality of linearization.

b) Observe the quality of the plate: Include whether the exposure is even and check the plate for scratches.

c) Check Postscript error: Used to check whether the interpretation of the file by the Postscript interpreter misses the content. The main observation is whether the content on each plate has no output. For the separation sheet, besides the single observation, the four color separation sheets should also be observed whether the tone and concentration of the image are normal and whether the registration is correct.

2. Proofing system check.

Now the CTP output center generally uses color digital proofing before the printing plate. If problems are found, modify the electronic file. The color samples after successful proofing will become standard proofs for color printing. This is different from the traditional film production and proofing of the printing plate. It is also a problem to be solved and improved by the CTP.