Open Coil: the most basic and simple springing system. Rows of hourglass springs are joined by a spiral wire, running top to bottom. Mattress edges are strengthened by a flat or round rod for all-round support. Open coil is mostly used on platform tops for a firmer feel. Open coil is also known as open sprung and sometimes called the Bonnell spring. Open coil mattresses usually have 325 springs but some of them have more. What does vary within the range is the tension. Some have a very firm 12.5 gauge and then as the tension gets less you begin to get the softer mattress effect.

Continuous Spring: The continuous spring unit is made from a single length of wire which is ‘knitted’ into a series of interwoven springs which usually run up and down the bed and are linked vertically rather than horizontally. Generally speaking the gauge of wires used is softer and the size of the coils smaller than open coil, giving a higher spring count and a more responsive feel.

Pocket Spring: Pocket springs are softer springs housed in individual fabric pockets – hence the name – allowing them to work independently of each other. That means they can profile better to the body shape and avoid building up pressure points making for a better overall sleeping experience. It also means that in a double bed or a king size bed there is little transmission of movement from one sleeping partner to another.