According to the Silly Putty website, the iconic substance began in a lab in 1943 as a failed formula for synthetic rubber. Seven years later, Peter Hodgson packaged the stretchy goo in a plastic egg and christened it Silly Putty. Since then, many parents and teachers have concocted recipes for homemade putty. Unfortunately, most of these mixtures contain glue, which can be messy or even toxic. You can make a clean, safe silly putty instead.
Use a whisk to mix 1 cup flour, 1/2 cup salt and 2 tsp. cream of tartar together in a mixing bowl. Separate 1 ¼ cups of this mixture into a second mixing bowl.
Combine 1 cup water and 2 tbsp. vegetable oil in a small cooking pot.
Slowly blend 1 ¼ cups of the dry ingredients from Step 1 into the cooking pot. Whisk the mixture until it is lump-free.
Use the wooden spoon to mix the remaining dry ingredients from Step 1 into the pot. The mixture should have a soupy consistency.
Cook the mixture over a medium heat until it reaches a doughy consistency.
Remove the mixture form the heat. Allow the dough to cool for 1 hour on a sheet of aluminum foil.
Store your silly putty in an airtight container.
Customize your putty by adding food coloring to the water and oil mixture in Step 2. To keep your silly putty fresh and germ-free, place three drops of hand sanitizer into the airtight container before storage.