From a YankoDesign.com online review:
The PrinCube sits on the throne of being the smallest (and the lightest) handheld color-printer. With a swift motion of your hand, the printer rapidly prints out one line at a time, measuring up to 0.56 inches in thickness. PrinCube’s multi-line feature lets you extend your prints by printing up to nearly 10 feet of content line after line. The wireless printer conveniently pairs with any device like your phone, tablet, or even laptop over a Wi-Fi connection, and each individual ink cartridge can handle approximately 415 A4 pages worth of printing before replacing. The battery on PrinCube’s pretty remarkable too, with the ability to print for 6 continuous hours before needing a recharge via the Type-C port in the PrinCube’s size.
https://www.indiegogo.com/projects/princube-the-world-s-smallest-mobile-color-printer#/
It looks like a block roughly half the size of a spray-paint can. In fact, that’s how you would hold the PrinCube too. Grab it with one hand and run it across any surface and the PrinCube performs a neat, seamless, colored inkjet-print on it. The PrinCube isn’t just small, it’s hand-held, wireless, and incredibly versatile. It can print on materials your desktop printer doesn’t even dream of. Paper, cardboard, wood, metal, cloth, working on flat, textured, and even curved surfaces. You could literally give yourself temporary tattoos too because the PrinCube even prints on the skin (it’s safe, if I may add).