A filter suggests the process of refinement and purification. This is connected to a change in material of the kind Beuys explored throughout his work. This drawing was made in the late 1950s when Beuys was living on the farm of the van der Grinten brothers near his home town of Cleves in West Germany. During this time he made hundreds of drawings which he referred to as 'reservoirs' of ideas. Many of the themes from his later work can be found in these pieces. Beuys used gauze filters alongside fat in his sculptures and 'actions' of the 1960s onwards.