This is a 'fancy' caul. A late period hat typically worn on the back of the head. I think I've made the band too wide. Below is an image of me wearing it (unfinished) at St Beocca's Eve Feast (April 9, 2005) with Master Piers of Malmesbury.
I cannot remember all of the references I used for this one as it was LONG ago. However this is one I do recall. I really liked the pearl work here which inspired the clusters of pearls on the original. It's earlier than the other references I used, but it's the only one that sticks in my memory.
Lorenzo Costa, c1490 Portrait of A Woman with Pearl Necklace