If you’ve got a spare printer ink cartridge and a document you only want one person to see—or just some free time and a cloak-and-dagger kick—one helpful Metacafe post has a project for you. The ...

Turning the childhood invisible ink trick on its head, this mod from Make allows you to print out invisible messages with your inkjet printer. Matt Richardson put together this excellent video with ...

Invisible ink is back, and it’s better at hiding than ever. A new invisible ink that you can print is harder to reveal than most common cyphers. Liang Li at Shanghai Jiao Tong University in China and ...

When I was a kid, my friend had this pen with invisible ink. You could write a note with it and then the person you sent it to had a different pen that made the text show up. We though it was awesome ...

Researchers have developed a rewriteable paper coating that can encrypt secret information with relatively low-tech invisible ink -- water. A message printed out by a water-jet printer on a ...

QR codes, those goofy black-and-white arrangements of digital information, could help secure bank notes. Scientists just showed that they could print an invisible QR code made of a high-tech ink ...

Researchers at Northwestern University have developed a new kind of sophisticated invisible ink that they say can be used to create codes that would be nearly impossible for counterfeiters to ...

Using inks created from artificial materials that exhibit properties not found in nature (aka metamaterials) and commercially-available inkjet printers, researchers at the University of Utah have ...