All the comments I’ve read so far have wonderful answers, but I didn’t see this one, though I understand you don’t want to destroy them for reading purposes, and I wouldn’t either, still, this is an alternative: use them for crafting, you can craft a lot of really neat things out of books, just do an image search on whatever browser search engine you prefer on topics like, Upcycled book/books, refurbish/referb a books/book, crafting with books, etc.