Wire binding also known as wire-o is one of the most popular binding methods and for good reason. The benefits of wire binding include documents that open flat and will fold back to back. Wire binding is super strong, looks good and is well known. There are two types of punching for wire binding 3:1 (3 holes per inch) or 2:1 (2 holes per inch) With 3:1 you are able to bind documents up to 120 sheets this is also the most common type. With 2:1 you are able to bind up to 250-300 sheets dependent on machine. 2:1 punching is generally used for thicker documents. Some of our wire binders even come with FREE wires to get you started.