What are the ingredients of Silly Putty?

Silly Putty is made primarily from silicone and color pigments. Silly Putty was discovered in 1943 by James Wright who mixed boric acid and silicone oil together. It was introduced to the public in 1950 by Peter Hodgson. Crayola acquired the exclusive manufacturing rights to Silly Putty in 1977. The formulas are considered proprietary.