Measure out 1 tablespoon of cornstarch, 4 tablespoons of cold
water which I already pre-measured, 1 teaspoon of glycerin, and
1 teaspoon of vinegar, add everything to the pot. Turn the heat
on to medium and begin stirring, keep heating and stirring until
the mixture turns from cloudy white to clear, watch how the starch
makes a transformation from liquid to a goopy like gel. This is
called gelatinization. Now turn the heat up a little bit and keep
stirring rapidly until it is completely clear. Quickly pour your
plastic onto the cooling sheet of your preference. Depending upon
the humidity in the air it should dry in about a day. When it’s
dry you can do whatever you want with it.