Innerspring 101

The History of the Innerspring
Mankind has always sought a better surface upon which to sleep. From the dawn of history, and for thousands of years thereafter, these surfaces were made up of grasses, leaves, twigs, furs, Spanish moss, corn shucks, or anything at hand that was softer than the ground. Later, in the late nineteenth and early twentieth centuries, mattresses became manufactured items. These sleep products were filled with horsehair, feathers, or cotton and were held in shape by an outer cotton fabric covering, or ticking, usually sporting a striped design.

During the late nineteenth century, the steel spring coil bed, held together with a border rod, was invented and patented. The bedspring offered a new dimension of comfort that had not existed before. Now there was an action surface upon which to place those primitive mattresses. The two together offered the finest sleeping surface discovered up to that time.

Further development of the bedspring resulted in a modern boxspring mounted on wood slats and covered to match the innerspring mattress. Todayís boxspring is designed as a working partner with the innerspring mattress. Boxsprings, as well as mattresses, enjoy a versatility of design characteristics that enhance the comfort and life of the bedding set.

Coils
The coils used to make these innersprings can take on a variety of designs, depending on the desired support and price point. You may have heard of a mattress "coil count". This is the number of individual coils that make up a full or double bed size. Generally, the higher the coil count and higher the gauge of steel, the better the support and comfort. The shape of the coil determines its performance. There are five basic coil designs the bonnell, the offset, the open offset, the marshall, and the continuous.

The bonnell coil is one of the most widely used in the mattress industry. It has an hourglass shape and is cylindrical at the top and bottom, tapering towards the middle. The offset coil is a less tapered version with squared-off heads that hinge when helically laced together. The open offset coil is unknotted, its shape a modified version of the offset coil. Marshall coils are barrel-shaped coils enclosed, each in a separate flexible fabric pocket. The pockets are all attached to the pockets surrounding them. The continuous coil consists of entire rows of coils formed from a single strand of wire.