what you need:
3/4 cup cold water
1 cup Elmer’s glue
liquid food coloring
1/2 cup hot water
1 teaspoon borax (you can find this in a box in the laundry aisle)
directions:
step 1: in bowl 1 – mix together the cold water, glue, and food coloring. set aside.
step 2: in bowl 2 – mix together the hot water and borax, until the borax is completely dissolved.
step 3: slowly add glue mixture to borax mixture. mix well. pour off excess water.
http://www.livecrafteat.com/craft/homemade-flubber-for-kids/