Staples are small metal fasteners that are used to join sheets of paper together. They are made of thin metal wires that are bent into a U-shape and then driven through the paper by a stapler. Under the microscope, staples reveal their metallic structure and texture. The surface of a staple may have scratches, dents, or rust depending on its age and quality. The edges of a staple may be sharp or smooth, and the ends may be pointed or flattened. Staples may also have distinct colors or coatings to prevent corrosion or to match the paper color. The last image shows how the ends of the staples are sheared from both sides with a tool like pliers to cut it.