I use exacto knives, rotary cutters, tweezers, rulers, and custom cut panes of glass to create carvings that reveal the beauty of old books. I only use books that are no longer valued for their content, and never carve rare or new books. I've deliberately put down books (that would have made lovely carvings!) if I think someone is likely to appreciate them intact. My favorite subjects are reference books that are several editions out of date, rescued from garage sales, free giveaways, and second-hand shops. Although most people aren't interested in these old books for the information they contain, carving them gives them a second chance as a piece of art.