Place a sheet of freezer paper inside the shirt so that the paint doesn’t seep into the opposite side. Use the paint and draw designs on the shirt. When you’re done, peel away the freezer paper and let paint dry. Now turn the lights off and take a look at your creation.
The glow in the dark stars and planets, and the glow in the dark paint are made of materials called phosphors. Phosphors absorb energy and then slowly releases that energy in the form of light. So the material charges up when the light is turned on and then emits that light until it uses up all the charge that was stored.