Snowkids Magic Crayons
These crayons are magical. They respond to temperature either by disappearing or reappearing.
When the "hot" red crayon is used to draw or color, the images become invisible when blown with hot air such as that of a hair dryer.
When the "cool" blue crayon is used to draw or color, the images are transparent but becomes visible when the image is brushed with something cold such as an ice cube.
Easily washable. Suitable for ages 3+ with adult supervision.