DLTK's Crafts for Kids
Air Dry Clay

Combine flour, salt, and alum in a mixing bowl

Add vegetable oil.

Slowly add boiling water, stirring the entire time.  Dough should not be sticky.

Break dough into separate portions if desired.

Add food coloring and knead until it is incorporated (your hands may get a bit messy here).

Form into small shapes, vases, bowls, flowers, etc or cut with cookie cutters.

Let dry 48 hours in a warm, breezy location.

Optional:  Paint with clear nailpolish or varnish.

Store for up to a month in an airtight container.