Dorothee Becker's most significant design, 'Uten.Silo', became an icon of plastic design. Its genesis was something of a fortuitous event, as Becker herself describes: "In 1968, fired by the spirit of the 1968 movement, I designed a wooden toy consisting of a large piece of wood with geometrically shaped notches and matching elements.

The first Uten.Silos went on the market in December 1969 and over the following years were an overwhelming success, particularly in Europe and on the US market, where they sold under the name "Wall-All" At the end of the 1960s, Dorothee Becker, who never trained as either as designer or an artist created several more pieces for "Design M".