Kimono condoms are known for their sheer thinness. Equally important to thinness is condom reliability. Making a condom ultra thin takes a lot of work, but making a condom that is both ultra thin and strong takes talent, expensive machines, and the highest quality of natural latex. In contrast to the U.S., Japan's condom industry has continued to explore product development and improved quality levels. During the 1950s, because of the risks associated with oral contraception, the Japanese government prohibited the use of birth control pills and offered government support for research and development of condoms. As a result, condoms became the most common form of birth control, used by 80 percent of sexually active Japanese couples. Such government and consumer demand have catalyzed technological advances in condom production, unparalleled in the rest of the world. To this day, Japanese condoms are thinner and considered superior by many condom users.