I can see gridlines on some components of the prepress proof which weren’t there when I created my files.

The transfer of files from one computer programme to another is not always without its peculiarities. Incompatibilities can sometimes occur. Sometimes it is a case of a file not having been compressed; other times there might be problems with the colour profile. In 99% of cases, these lines never appear on the final printed version. But even if there is only a 1% chance, we are always 100% attentive and we will get back in touch with other solutions if this happens.

Link to this answer: https://old.azaogames.test/en/faq/i-can-see-gridlines-on-some-components-of-the-prepress-proof-which-werent-there-when-i-created-my-files/