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 ...

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 ...

April 26, 2008 Add as a preferred source on Google Add as a preferred source on Google If you’ve got a spare printer ink cartridge and a document you only want one person to see—or just some free time ...

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 ...

While I doubt the super serious stiff in this DIY video is actually a super spy, he does have the DIY know-how necessary to hack apart an inkjet printer and make it into an invisible ink-spitting ...