Fonds reflects Siebner’s intellectual and philosophical interests and ideas on art and life; his interactions with galleries, friends, family and patrons; travels; involvement in the Limners; pre-publication work for his monographs and other books; promotion and sale of art; and public art commissions.
The fonds consists of personal writing and poetry, correspondence, sales lists, inventories, exhibition announcements, sketches, clippings, photographs, film and video, prints and drawings.