Are we talking printing our own designs onto the film with a regular inkjet, or a special printer/inks?
I poked around looking for supplies and could only find pre-printed materials.
small kits are just toys, and as indicated, cheesy.
if you want it to look nice and last, you need $olid equipment and chemical$.
But with the correct materials yes a coffee cup could do a small item.
it will be cheaper to find an art/advertising/sign shop that
has work spaces set up for it