What is the meaning of abbreviation PS in relation to Off sett printing?

In offset printing, "PS" doesn't have a specific meaning. It's more likely an abbreviation used in a particular context that you haven't provided.

To help me figure out what "PS" means, please give me more context:

* Where did you see the abbreviation "PS"? (e.g., a technical document, a label on a printing plate, a conversation)

* What was the topic being discussed? (e.g., printing process, prepress, materials)

With more information, I can accurately tell you what "PS" stands for in your specific situation.