..carved from lightweight greyboard..
The Decahat dome construction..
..being covered by its satin lining.
..with added supports on the inside..
The hat‘s construction, erected from subsequent layers of thin, though rigid, greyboard, fastened using both adhesive and staples, here displayed in the process of being finished, receiving its lining on gently pressing the softly glued seams into the securely carved ribs, covering all bearings and face-supporting connections.
Impressive!