A 4% solution of sodium tetraborate (Borax). This solution can be prepared by dissolving 4 grams of Borax in 100 mL of water.
A 4% solution of polyvinyl alcohol. This solution is prepared by dissolving 4 grams of polyvinyl alcohol (PVA) in 100 mL of water. The PVA does not dissolve well so heating and stirring are required. (Note: PVA comes in a variety of average molecular weights. I use PVA with an average molecular weight between 106,000 and 110,000. A student of mine has experimented with various slimes produced by using PVA with higher and lower molecular weights. She found that higher molecular weights produce a "stiffer" slime while lower molecular weights produce a more fluid, i.e., "slimier" slime.)
The alcohol and borax solutions should be mixed in the ratio of about 200 mL of PVA solution to 15 mL of borax solution. Prior to mixing, food coloring can be added to the PVA solution for "pretty slime". Best results are obtained if the borax solution is added to the PVA solution. The 200:15 ration can be achieved by the following English volume measurements:
(1) one-half cup of PVA solution to one tablespoon of borax solution.
(2) one-quarter cup of PVA solution to 1.5 teaspoons of borax solution.