I spy invisible ink pens that belong in the kids' stockings — snag a pack for $8 They have built-in UV lights and are suitable for children ages 3 and up, but you'll have fun using them too!

Collins tells host Scott Simon that the book looked almost exactly like those from his 1970s childhood. ... For example, students could use invisible-ink pens to work on their handwriting.

Invisible ink, false mustaches, colored contact lenses, and secret code words sound like the ingredients of a Nancy Drew novel or a Spy Kids movie. Accessibility links Skip to main content ...

Geek Life: Fun stories, memes, humor and other random items at the intersection of tech, science, business and culture. SEE MORE Lines drawn with Living Ink’s algae pen disappear in about 10 ...

When Columbus officials suggested that residents mark the copper parts of their air conditioners with invisible ink to help head off a plague of thefts, they didn't say where to buy the pens.