The most common types of couches are the two-seater, designed for seating two persons, and the sofa, which has two or more cushion seats.A Couch
consists of the frame, the padding and the covering. The frame is usually made of wood but can also be made of steel, plastic or laminated boards. The wood used under the upholstery is made from kiln-dried maple wood that is free of knots, bark or defects. The show wood of the legs, arms and back can be maple, mahogany, walnut or fruitwoods. Sofa padding is made from foam, down, feathers, fabric or a combination thereof. Sofa coverings are usually made out of soft leather, corduroy or linen fabric coverings. Some outdoor sofas are made from specialist reticulated foam. Due to its highly advanced open cellular structure, water freely passes through it making it highly resistant to soaking.Many modern sofas are filled with fibre cushions or low density foam. This is largely due to a massive cost saving by the manufacturer in using a fibre material rather than a solid foam cushion.