A toy made from 100% natural rubber The latex from the Hevea tree was first processed in 1928 using the vulcanization technique invented by Mr. Charles Goodyear. The rubber used by Vulli comes exclusively from the Hevea trees growing in Malaysia. Each morning before the heat of the day settles in, the milky liquid that oozes from the cells beneath the bark is collected from these millions of Hevea trees. This liquid is known as “latex”.