FriXion highlighters use a special thermo-sensitive ink that turns invisible when rubbed with the built-in friction "eraser." The ink disappears cleanly without using up the eraser or creating any dust or smearing. The ink will also disappear if exposed to other sources of heat or friction, like in a hot car. Like magic ink, erased FriXion ink reappears if placed in a freezer or otherwise exposed to temperatures below 14° F.
