Irma chair, 1979 Steel frame, cowhide, 35 3/8 x 16 1/2 x 17 5/16" Manufactured by Zanotta Lent by M2L Collection   So named in homage to Castiglioni's wife, the Irma's steel structure supports the leather seat and back. The back, in particular, is reduced to the strip that supports the spine and shaped to follow its natural curves.