Stretch Armstrong keeps best at room temperature. Stretch Armstrong is made of latex rubber filled with gelled corn syrup, which allows it to retain shape for a short time before shrinking to its original shape. An estimated 67 different versions from Japan, Germany, Italy, France, Australia, and other countries released Stretch Armstrong variations between 1976 and the 1990s. The last two were filled with a granular solid in place of the viscous liquid found in the other figures. A vacuum pump, which attached to the heads of these figures, removed the air from within, which "froze" the toy in its stretched position.
Crepe rubber of the latex used in their manufacture. Crepe rubber Crepe rubber is coagulated latex that is rolled out in crinkled sheets, commonly used to make soles for shoes and boots but is also a raw material for further processed rubber products. Colloidal latex is first mixed with formic acid to cause it to coagulate. The coagulum is processed in a "creping battery", a series of machines that crush, press and roll the coagula. The sheets are hung in a heated drying shed and then sorted by grade and packed for shipping. There are several types and grades of rubber crepe,