Cover one end of tissue tube with duct tape. Place a loosely rolled piece of wax paper into the tube to create a liner to keep the plaster from sticking to the tube.
Pour water into mixing container then sprinkle plaster; a little at a time, into the water until plaster no longer dissolves (approx.1-1/2 cups). Stir thoroughly. Mix in 2-3 tbsp. tempra paint. Or until desired color is reached.
Place tubes sealed end down on a flat surface. Pour plaster mix in. Tap side of tube to release air bubbles. Let dry 1-2 days, pull off mold and have fun drawing!
Be sure to rinse container and spoon outside or in a container of water to avoid clogging indoor sink drains.