Blueprints can be used to learn how to craft an item. They can be obtained by using a research table with scrap and the item you want to research. The amount of scrap needed to research an item differs depending on the rarity or quality. Make sure you don't already know how to make an item before researching it as the research table won't prevent you from making blueprints you already know. Blueprints can also be obtained from crates and barrels. It is now possible to go down a tech tree for each workbench, and target specific items there. It costs a different amount of scrap to research each item, and can be very useful if you cannot find a certain item.