Thick Paint How to thicken School Tempera Paint with school paints Here is a quick recipe to thicken a water based school tempera poster paint. This takes about 10 minutes to cook and has a great thick smooth texture that is ideal for finger painting. Depending on the amount of paint you need - increase or decrease the quantities of this recipe. Learn how easy it is to paint a butterfly with mirror painting. What You Need: 4 x spoons of Corn-starch, 3 cups water, small sealable containers. Recipe for thickening Temper Poster Paint : 1. Add 4 x level teaspoons of corn-starch with 3 x cups of water in a pot, mixing until all combined. 2. Heat the mixture over low heat, stirring it until the corn-starch dissolves and is smooth and thick. 3. Allow the mixture to cool. 4. Add the thickener to your tempera in a slow pour, stirring the paint until you get the viscosity desired. Don't add too much at once, as you will have to add a m
