A book has a head, a tail, and a spine, so I guess I should be used to referring to them anatomically, but it was a little funny to me to find out that books can have shoulders. It’s for rounded spines in the English tradition, I believe. French bindings round without the shoulders, which means you sort of have to sand the covers where you attach them to the spine so there isn’t a hard step under the book cloth. If you give the book shoulders, however, you don’t have to sand the covers. Using a backing press like this one:
You drop your book into the press with spine raised up the same distance as the thickness of the cover boards–and then you beat it viciously with a rounding hammer. Starting from the center of the spine, you sweep the hammer out toward the edge until your shoulders are just past 90 degrees.
This is the one I made with nice fat shoulders:
It feels so good in your hands–fits just perfectly, and the double-thick covers feel so solid.