1 1/2 cups. water, divided
4 oz. (or 1/2 cup) Elmer's glue--we used clear glue, but you can also use the white.
Fill a small bowl with 1 cup of water and add 1 teaspoon of Borax powder. Mix until the Borax is dissolved and set aside. Pour glue into a medium mixing bowl and add 1/2 cup of water. Add four-eight drops of food coloring to the glue mixture. Stir it up a bit and add a bunch of glitter. Now add the Borax mixture to the glue mixture and watch it begin to solidify.
Stick your hands in and and start mixing it all up. Pour out the excess water and knead the mixture until it becomes more firm and dry.
When you're done playing with it, store in a Ziplock bag or other air tight container. We used 2 oz. Multi-purpose mini cups I bought at Wal-mart.
The Science Behind It: This mixture is a polymer. Polymers have long chains of molecules that can slide past each other until some of the molecules come in contact with molecules that stick together at a few places along the strand. Borax is the compound that is responsible for hooking the glue’s molecules together to form the putty-like material. There are several different methods for making this putty-like material. Some recipes call for liquid starch instead of Borax soap.If you are concerned about using Borax, perhaps this article can help reassure you.