The files are big because of cached resources which are stripped when you do save as. Simply put, everything you add to a painter project is saved with it so file sizes can inflate rapidly. 2018.1 also has a fun bug where file size increases every time you save even if you make no changes. You could(haven't checked 2018.2)…
For older version just save you painter file on Desktop or other location other then what you currently at, it will magically reduce the file size and just copy that back into the location you needed.
Hi Axel, When you're doing multiple bake, you will have to clean the project to purge the unused bakes because of the remaining fragmentation. You will have empty space unused, but still present in the project. I'll recommend you to go into the "File" Menu, "Clean". After that you can "Save & Compact" if you're using…
Lol yeah nobody knows why, and the Save&Compact feature on the latest Painter basically do this but on a single step (as if you were just normally ctrl+s, but took slightly longer). Normally I just did this once at the end of my texturing session each to keep the file size in control :wink: