When binderies employed ten or fifty workers they had a hierarchy of trades ~ Sewing people (invariably ladies) ~ Collaters ~ Forwarders (the binders) ~ and, maybe, one Extra Binder. He was the person entrusted to make a well-bound book decoratively excellent.
It takes a lot of skill and confidence to finish a Fine Binding ~ one mistake and the whole effort of all the workers beforehand is ruined. The Extra Binder had as much time as he needed to do the job ~ and a commensurate wage. (Alas ~ they are always spoken of as being men. There were some women who reached the summit ~ eg Edith Diehl ~ notes to follow ~ her book is out of print but is still available and I commend it ~ wait until a copy coomes up in the second hand market for under £20 ~ the best price I have seen recently is £15.)
This page of my bookbinding notes will be based on material taken from Zaehnsdorf's book The Art of Bookbinding since I know nothing of the trade as it was in the days of numerous fine bookbinders. There are still many such professionals around today ~ but they are hard for the layman to find ~ and unlikely that such common person would be able to afford their craftsmanship. Expect to pay a four figure sum for modern fine bindings.
Interrupted in mid-flow. Patience, dear reader, I will return (even if you do not!)