In 1977 Gunther von Hagens invented plastination, a technique or process used in anatomy to preserve bodies or body parts. In the process water and fat are replaced by certain plastics, yielding specimens that can be touched, do not smell or decay, and even retain most properties of the original sample, including the original weight. During the first 20 years plastination was used to preserve small specimens for medical study. It was not until the early 1990s that the equipment was developed to make it possible to plastinate whole body specimens, each specimen taking up to 1,500 person-hours to prepare. The first exhibition of whole bodies was displayed in Japan in 1995. Over the next two years, von Hagens developed the Body Worlds exhibition, showing whole bodies plastinated in lifelike poses and dissected to show various structures and systems of human anatomy. This met with public interest and controversy in more than 50 cities around the world.