That line you see is the entrance cut from our saw. It's one of the ways prices stay reasonable from year to year since we don't spend half an hour cutting the book with a jigsaw. Using a jigsaw or scroll saw also requires two pieces of wood with the book sandwiched in between them, resulting in extra cost to buy the wood, as well as the waste of wood after one book safe is made. We make thousands of book safes, and that would be a lot of wood! We're about recycling, not consuming. The saw cut is not visible once the safe is on the book shelf, whether it's upright or laid on its back with the spine facing out.