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.
Vytex Natural Rubber Latex Samples of treated Vytex NRL are subjected to the Modified Lowry ASTM D5712-05 test, used to measure the total extractable proteins in natural rubber latex, and the ELISA Inhibition ASTM D6499-07 test, used to test for antigenic latex proteins. Un-leached sample films and products made with Vytex NRL have been independently tested for protein levels at three time intervals: immediately after production, after 21 days of storage, and after 6 months of storage. Test results during all phases of protein testing generated less than 10 ug/dm² of antigenic protein using the ELISA protein test method. Products made from Vytex NRL