Researchers say we don’t put on enough sunscreen. A Seattle startup has come up with a potential fix: an invisible ink stamp that notifies you when it’s time to re-apply. Michael Croix, a ...

Ink stamps can be fun to make and use, and 3D printers are uniquely positioned to create quality stamps of all kinds with just a little care. As with most things, the devil is in the details and th… ...

The "anti-groping" stamps, manufactured by stamp-maker Shachihata Inc., allow victims of harassment to mark their assailants with invisible ink, and also provide a deterrent to would-be attackers.

It comes in six different colors and it’ll be available soon for the somewhat steep price of $499, but again — it’s hard to put a price on a giant E Ink clock.