1/4 Cup Talcum Powder (Baby powder)
1 Tablespoon white all purpose glue (wood glue or craft glue)
1 Tablespoon white craft paint (or any colour you want the paste to be)
1 – 2 teaspoons water
Combine powder, glue and paint with disposable stirrer or plastic spoon in an airtight containger. Add water to get it to the consistency you are looking for. It should be a nice thick texture much like toothpaste. This mixture will keep perfectly for many months.