First of all, great hat!  Well made, great shape, excellent fabric.  Material has both a texture and a slight sheen to it.
Now, on to sizing.  I ordered an XL, which according to the Amazon size chart can range from 7-1/2 to 7-3/4.  The Brixton XL is in fact a 7-3/4 while a L is a 7-1/2.  No matter for me as this one fits my XL sized cranium.