This set of 15 thin metal dies are in the shape of bookmarks. These will work well with slimline cards (sold separately). The largest die measures 3.5" x 8.5" and the smallest measures 0.37" x 1.75". These dies work with most die cutting machines (sold separately). This set will give you a wide variety of sizes for your bookmarks and even contains a circle so you can put a hole in the bookmark and insert ribbon or twine (sold separately).