GBC has a different style of binding for you to try out! Metal binding is a simple form of binding that takes a metal strip and clamps your papers together-no punching or glue necessary. Thicknesses vary from 5mm to 33mm, which holds anywhere from 20 to 300 sheets of 20lb paper. They make great binding spines for manuals, notebooks, photo books, portfolios, catalogues, or any other document that needs to be securely bound. We even offer them in different textures, such as linen, leatherette, and painted gloss. As for colors, we have black, navy blue, burgundy, white, and forest green. So get security and strength with these metal binding strips.