Natural rubber Natural rubber Natural rubber, also called India rubber or caoutchouc, as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds, plus water. Malaysia and Indonesia are two of the leading rubber producers. Forms of polyisoprene that are used as natural rubbers are classified as elastomers. Currently, rubber is harvested mainly in the form of the latex from the rubber tree or others. The latex is a sticky, milky colloid drawn off by making incisions in the bark and collecting the fluid in vessels in a process called "tapping". The latex then is
Substance 1987 (2004) that the album is "pure pleasure" and serves as "a guidebook to 1980s pop", along with Prince's "Purple Rain" (1984) and Madonna's 1990 compilation "The Immaculate Collection". "Slant Magazine"'s Sal Cinquemani was less enthusiastic and said that the album is "undeniably a product of its time". In 2005, Will Hermes included "Substance" in his "definitive guide" to dance-rock for "Spin" magazine. Substance 1989 is the video version of "Substance" that first appeared in 1989 on VHS; it was released on LaserDisc in Japan in 1991. The cover is similar to the LP, except "1987" is replaced by "1989" (though