I remember seeing (could be 10 or 20 years ago, on something like BBC's old Tomorrows World program) small - robotic - printers with wheels that moved over the surface to be printed. They were ideal for printing on paper or canvas that physically could not run through a printer.
Apologies if SuperUser isn't the place to ask this
I have a requirement for something that can do this, I tried googling but with no success.
Do these things still exist? If so what are they called? Where can I pick one up?
Clarification
This wouldn't be printing on paper, it would be printing on a flat surface of a manufactured product, the surface cannot be covered by paper or plastic.
also, they were actual manufactured products, not this home made version