J T wrote:
S.*Dees makes his claim that:

snip (The shelves need to be sloped backwards so that books that are
stacked with the front cover facing out will not accidentally fall
forward and out.) snip

Yep, if you don't slope those books, they'll leap right oout at ya.

You must be from a different part of the universe than I'm from.
I've never heard of that. And, apparenly none of the bookstores,
schools, libraries, or anywhere else I've ever been has. If the shelves
are level, and the books not hanging out way over the edge, they have no
reason to fall out. Who told you that? Of course, you could be
another one of those dull little trolls too.

Most library books are arranged with the spines facing out,
supported by adjacent books or a bookend. I think that the OP wants to
arrange the books with the front cover facing out for display
purposes. If that's the case, angling the book backwards, with a cleat
to keep the bottom of the book from sliding forward, would be a good
idea. If the shelf is below eye level, tilting the book back would
also make for better viewing.

R,
Tom Q.