The final Back weave on the brim is done buy a
"Master Hatter"
who specializes in just this process, your hat brim will never be cut folded and sewn in any manner as some ,
cheap hats are done.
I find that most people ask about this style only because they have heard about the Famous Roll up panama hats and it is a conversation piece for them and that is fine, but it may not be as practical as you might need from a daily wear hat.