For the budget conscious, many mold making products simply cost too much. Not only that, but the substances involved can be very toxic. Rather than deal with a messy, hazardous material, you can instead make nontoxic molds from corn starch modeling clay. Cornstarch modeling clay requires few ingredients and hardens in a few days. Not only can you get good detail with these molds, but they are also safe to use with food. The use of cornstarch clay dates back to the nineteenth century.
Things You'll Need
2 cups salt
2/3 cup water
1 cup corn starch
½ cup chilled water
Model for molding
Measure out ½ cup of water into a bowl and place it in the freezer to chill for ten to fifteen minutes. Do not let it freeze solid.
Remove the chilled water and mix in 1 cup of corn starch. Stir it with a mixing spoon until the mixture has an even consistency.
Place a pot on the stove and turn the stove to "low." Pour in 2/3 cup of lukewarm tap water and 2 cups salt. Stir the mixture with a mixing spoon until the salt dissolves. Heat for 4 minutes.
Remove the pot from the burner and immediately pour in the chilled cornstarch mixture. Stir vigorously with a mixing spoon until you have a putty-like material.
Separate out a glob of the putty and put it on a tray. Press the object you wish to make a mold of into the putty. Pull it out slowly, lifting straight up.
Place the mold in a cool, dry cabinet for two to three days, until it dries completely. When it is dry it will be hard enough to use.
You can also use this modeling clay as a casting material in molds.