1/2 cup white school paste (4 oz)
1 cup water (as 1/2 cup and 1/2 cup)
1 tsp borax
food coloring

Add 1/2 cup of the water to the school paste, add food coloring.  In a separate cup add 1/2 cup of water to the borax until dissolved.  Add the two mixtures together.  The final product should be very a very thick glob surrounded by excess liquid.  Mix until the glob is more solid.

Pour off the excess water.

Knead the glob until thick.

Store the glob in a air-tight plastic bowl, cup, or large baggie.

Note: this glob contains borax and therefore should not be eaten.  This recipe is intended for children responsible enough to not eat this mix.