hey there! im interested in starting to get into overlays here cus i love pet sites that allow the use of custom art in the actual game, and i dont really see anyone making premades. so im wondering, are premades allowed? like make some art that could be used as overlays and let people buy them?

yes, but if people are going to use them as official custom overlays (the kind you pay CSC to replace the pet's image across the entire site, as opposed to one you just code into the profile), each overlay can only be used by one person.