While waterbeds have been known for almost 4,000 years, in the 20th century the water filled bed reached the masses. In 1987, 22 percent of mattress sales were waterbeds. Inventors had tried, unsuccessfully, during the 19th century to make the water filled bed commercially successful, but the bed did not become practical until the invention of vinyl in the 1960s. In the 70s and 80s, its popularity coincided with the sexual revolution, and the waterbed became identified with the hedonism of the times.
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