A binder is a cover that holds and protects paperwork that would otherwise be loose. Binders are therefore common in offices. They keep important papers in one place. Binders are also easy to file on office shelving. Office workers can place a note of the contents on the binders' spines to trace documents quickly.

Hard Cover BInders

The covers of binders may be hard or soft. Hard ones are made of board covered with plastic or leather. The use of plastic means that binders come in a wide range of colors. Office workers generally employ hard cover binders for filing and often use different colors to create a filing system. Red binders, for example, could contain copies of invoices; blue binders could hold details of orders. Office workers also stick labels on the binders' spines to indicate what the binders contain. The covers generally hold paper that is 8 1/2 by 11 inches. A hard cover binder that is one-half inch deep can hold 100 sheets of standard paper. Hard cover binders are available up to 3 inches thick.

Soft Cover Binders

Soft covers are flexible. They are generally made from plastic or heavy paper. Like hard cover binders, they come in a range of colors. Plastic soft covers may also be clear to allow people to see the first sheet of paper in the binder. Soft cover binders are thinner than hard cover binders and usually hold no more than 30 sheets of paper. The standard size of the paper 8 1/2 by 11 inches. Office workers use soft cover binders for reports and presentation documents.

RIng Binders

Paper is held in place in a variety of ways in hard cover binders. A ring binder has two, three or four metal circular rings positioned along the inside of the spine. To file paper in such a binder, use a hole punch to create matching holes along the paper's left edge; pull open the rings; place paper onto the rings and snap the rings shut. There are also multiring systems for soft cover binders. They require a multihole punch that matches the type of binder.

Arch Mechanisms

Hard cover binders, especially 3-inch ones, may use arch mechanisms to keep papers in place. Arch mechanisms have straight metal sides. These sides keep the left- and right-hand edges of the filed paperwork straighter than if you use ring binders. Arch mechanisms are also more robust than rings. Arch mechanisms usually stay closed even when a binder is bulging with papers. The rings in a ring binder may open when they contain too much paper, causing paperwork to fall out. There are three arch mechanisms: Lever arch, swing arch and LD mechanical. For arch mechanisms, paper must have two holes punched into its left edge.

Clips and Alternative Fasteners

Soft cover binders often use clips to hold paperwork in place. With clips, there's no need to punch holes in the paper. Alternative methods of keeping paper in place in both soft and hard binders include screw head rivets, screw posts and straight metal fasteners. None of these methods are as quick and easy to use as other forms of fastening. They are best for permanent filing in binders used for long-term storage.