We're carrying these Thermochromic Pigments in a variety of colors. This pigment is always-classy Adafruit Black. It changes to a light/white color at 31 °C or 88 °F.
How to get started on your next masterpiece? Just add a little water then paint any surface. This pigment not meant for use on bare skin as a body paint and definitely not for eating! The paint dries quickly at room temperature and can be removed with soap and water. You can also mix into resin, slime, waxes, sugru, hand-formable plastic...pretty much anything you like!