Add the corn starch and cold water to a pot, and let the starch disperse in the water at room temperature.
Add the glycerol and vinegar.
Place the pot on a hot plate or stove and heat at very low temperature for about 5-10 minutes, with constant stirring , until a viscous consistency is achieved.
Turn off the heat, and pour the mixture on a greased baking tray or other non-stick surface.
Depending on the size of your sample, pour different amounts. For example, one batch using this recipe can create 4x 10cm circles.
To dry the samples, you can either air dry the samples overnight, or dry the samples in the oven at 150 °C for 1 hour. Air drying creates more flexible samples with a higher water content, and oven samples are stronger but more brittle.