I appreciate this question is borderline for this site (apologies), but I checked the FAQs and I think it is permitted.
I'm investigating ways to get single-colour text onto a thick plastic sheet, such as plastic business cards.
There seem to be a host of options: pad printing, screen printing, flat-bed printing (inkjet), thermal transfer printer (as in this post) and more that I cannot remember.
Of particular interest is inkjet methods because the printers are potentially so cheap. Flat-bed inkjet printers are often marketed as being able to print full-colour on iPhone covers, with a scratch- and water-resistant finish. However these machines seem to retail at $1k and up for A4 size. There also seem to be variations within this category, I believe that one is UV-curing of ink, and non-UV curing. I noticed that on a low end machine, some non-UV types actually uses an Epson print head.
This leads me to believe that perhaps a regular consumer inkjet printer could be used to print on thin plastic, if filled with an ink that will not smudge on plastic. While cartridges might not be available for them, there are cheap continuous-ink systems where perhaps the ink suitable for paper could be replaced by ink for plastic.
My question: does anyone know if there are inks that could be used on plastic with a regular inkjet printer?
I know there are specialist OHP transparencies that can be used with inkjets but not only are the opacity and brilliance is poor, but it is also not resistant to smudging.