Book-shipping mistake that seems small but can get expensive

Books can be surprisingly tricky to ship.

At Packlane, working with book packaging has made one thing pretty clear: a lot of damage doesn't come from the shipping carrier itself. It often comes from books having too much room to move around inside the package during transit.

Corner dings, bent covers, and scuffed edges can happen even when the outer package looks completely fine.

It's one of those details that's easy to overlook when shipping your first few orders, but it can lead to unhappy customers, returns, or replacements down the road.

For those who sell or ship books regularly, what's a book-shipping lesson you learned the hard way?