How do I know what solvent to use to etch plastic travel mugs?

I am in charge of a not for profit and don't want to pay the $50 set-up fee for getting our logo onto 30-40 travel mugs. I'm kind of crafty and wouldn't mind doing it myself if I could find out how.

There wouldn't happen to be any markings on the mugs that might say what kind of plastic they are, would there?
ahuntress (author)  DELETED_GuardianFox8 years ago
There are no markings. I decided to use a wood engraving tool. It takes skill, but it seems to be working. Thanks for the quick response though.
poster definitely wants to be careful using any petrolium products that would 'etch' the plastic and leave a permanent residue of goobery softened plastic forever.
lemonie8 years ago
Tell us more about the mugs, are they clear, opaque, what colour and like GuardianFox suggests look underneath for a triangular symbol with letters and a number?