A team of engineers has designed a new line of multicolored tattoo inks that switch on and off with different kinds of light. Described in a study published in Matter & Light, the technology could one day help people hide their tattoos when they have an important business meeting. They could even doodle on their own skin using a simple laser pointer.

“Tattooing is a very ancient technology that remains mostly untapped as a platform for today’s technologies,” says lead author Carson Bruns of the University of Colorado Boulder.

The new inks, known as PhotoTat, are made from dyes and a Plexiglas-like material common in many medical technologies on the market today, including dermal fillers. The research is a passion project for Bruns, who has a lot of his own tattoos, including a green lion on his arm.