Judging by the furniture inventories of palaces in the Middle Ages, cushions have been around a long time. Historians believe they were much bigger than the contemporary versions. Covered in leather, they were originally used as seating.
They were well known in France and at one time, the right to kneel on a cushion behind the King was considered the ultimate privilege. Unlike the comfort of upholstery foam used today, cushions were stuffed with a variety of materials. By the end of the 17th century, cushions could be padded with practically anything including grass and animal hair.
The modern cushion although smaller, is relatively similar in appearance. But that's where the resemblance stops. The upholstery foam that is used to provide comfort and support is very much a product of our technological era.
Foam cut to size, known as RX Flex has a softer feel than other materials due to its high density. Specially engineered to return to its original shape after use, it is ideal for cushion seats. For those who need some back support, a different type of cushion foam is required. Manufacturers use medium/soft density foam for this application. It still feels soft yet provides the support that customers demand.
Next in the range is Medium/Firm density. Anyone who needs a firmer chair seat will appreciate the support offered by this foam. It is used in many furniture designs, both in the home and in caravans.
For areas prone to high levels of use, such as sofas, High/Firm density foam is used. This is particularly useful for garden chairs or sleeping areas in boats or mobile homes.
Interestingly for a material that is so widely used, it remains largely invisible. When enjoying a drink at a hotel bar, few give any thought to the engineering that went into the seating.
Very High/Density foam is often combined with a softer material to produce strength, comfort and support. In many applications, an overlap between the various densities is necessary to achieve the desired effect. The soft rounded appearance in a significant percentage of cushioned seats is due to soft, low density foam known as Polyester Fibre Wrap.
While foams vary in density and feels, they all share a common property. Furnishings and upholstery must, by law, be flame retardant.