Minecraft wiki entry for Enchanting, associated text: The experience costs for using books are considerably less than for combining items with similar enchantments since the books themselves cost levels to create. However, it's still an extra cost, and enchanting items directly has a chance to get multiple enchantments. The advantage of books is that they can be stockpiled for use on an item of choice and allow for controlled combinations. For example, a Silk Touch book can be used on an axe, pickaxe, or shovel, and the player can decide which item receives which enchantment.