Mood Sheet See psychedelic patterns the safe way! Press your hand on this 6" x 6" sheet of liquid crystal and leave a print of swirling colors that, like the mood ring of yore, you can use as a sign of your mood. The pattern will blend and fade in seconds as the crystals react to temperature. Tiny liquid crystals inside the film-like material react to heat by changing colors. As science, it demonstrates the way liquid crystal displays work. And you can cut it into pieces to incorporate into a science project. Or just leave it out for guests to play with when the party turns boring.