Beuys often utilised the fabric felt in his work. For him it represents protection and preserving energy by preventing it from being dissipated and lost. Beuys explained the character of his felt pieces, such as `Felt Angle?, as follows: ?These felt objects? share common meanings and intentions, both physical and symbolic: felt as an insulator, as a protective covering against other influences, or conversely as a material that permits infiltration from outside influences. Then there is the warmth character, the greyness which serves to emphasise the colours that exist in the world by a psychological after-image effect, and the silence as every sound is absorbed and muffled.?