After three years of development, Doris Rüther completed her invention, QUADRO, in 1979. That same year, the system was unveiled for the first time at the International Toy Fair.
The first prototypes were built back in 1977/78 and tested in 16 German kindergartens, always in close cooperation with TÜV, the German inspection agency. The results were quite positive and led to the certification of the entire QUADRO system, even though this was completely new territory for TÜV.
In mid-1979, QUADRO became an independent family business. A new direction was set: QUADRO would no longer be a product for one market, but rather a system for many markets across the entire leisure sector — for children and adults, in homes and in yards, indoors and outdoors.