These masks are called Rorschach masks. Called after the famous inkblot test, they imitate the movement of the ink playing with people’s imagination.
According to the creator, the temperature-sensitive ink used in these is 100% safe and non-toxic. The masks come in several different designs.
Each one looks different, some creepier than others. You can even see the animated changes the mask goes through when it interacts with the breath.
Practice directional breathing to create a really cool effect of the ink fading in an out from your face. The masks are handmade from breathable spandex blend.
It comes in one-size-fits-all and adjusts to your facial features. Your visibility may be a bit obstructed but that’s a small price to pay for freaking people out on the spookiest night of the year.