Even the smallest bed, such as a twin or a crib mattress, needs a frame. The bigger the mattress, the more likely it is to have a center support rail running lengthwise or crosswise to provide additional support. Some bed frames have wooden slats, especially if the mattress rests directly on the frame, as is the case with platform beds.

Frames may be very plain, in which case they’re designed to be hidden, tucked away under the bedding or a bedskirt. Other types may be functional furniture, with a headboard, a footboard, and sometimes storage drawers built in.

Most frequently, they are made of metal, wood, or brass. Several elements are common to the design of all frames. They will have four legs, two at the top of the bed and two at the bottom. The support structure is usually a shelf with a 90 degree angle for the mattress to sit on. If a headboard is attached, then it will be bolted on to the frame at the head. The footboard will be bolted on to the frame at the foot.

Bed posts are decorative elements that attach to the four corners of the bed and extend up in the air, sometimes as high as five feet. Canopy beds rely on the bed posts to support a fabric umbrella that covers and encloses the sleeping area. The exposed pieces can be made more attractive with varnishes, paints, or fabric coverings. Antique wooden bed frames often have ornate, one-of-a-kind designs.

Brass beds have been around since the turn of the century. Originally made of a brass alloy that needed polishing, today’s design are more likely to be a brass plating, which is lighter and less expensive but also require less maintenance.

Iron beds can be found in antique shops all over the country. Once a bastion of America’s steel industry, they’re getting harder to find as furniture makers switch over to lighter metals. Metal bed frames can be enameled in just about any color, including matte finishes, glossy, and metallic sparkle.