Most modern sofas and chairs use polyester fibre (hollow fibre or fibre filled) as the primary material for filling the cushions. This material is fine for back cushions which take light use compared to base cushions. However base cushions can have a short life in the modern home when filled with polyester fibre and can quickly start to compress. Two years of family use can see a fibre filled cushion starting to show signs of wear and in extreme cases six months can be the order of the day. You can extend the life of a polyester fibre filled cushion by rotating them every day but in today's busy life who has the time for that? The polyester fibre when compressed under family usage day after day stops returning to it's original height and the cushions soon starts to take on a saggy look.
There is an answer though to this problem though, which maintains the puffed up look of a new fibre filled cushion, returns to it's original shape for many years and yet has that 'sink into' feeling that one experiences with new fibre filled cushions. Unfortunately just buying a block of foam cut to size is not usually the answer. The foam will have a very rectangular, block look about it and whilst providing the comfort required will not have the look of the original puffed up polyfibre cushion. The answer then is to manufacture a cushion using a foam cut to size core, the measurements of which will be the distances between the seems of the covers and then wrap this foam with a heavyweight polyester (about 14oz weight). This will then give the cushion a more rounded appearance but the foam core ensures that the cushion will return to it's original height.
Various grades of foam can be used for the foam core, the choice of which is very much down to personal preference. A medium to high density upholstery foam should be used for the foam core to give the foam cushion a long life but then in each density various 'feels' are available. The most popular foam used for the core tends to have a soft feel to it. Using this type of foam gives the cushion the properties that so appealed with the original fibre filled cushion, in that when you sit on the foam cushion you sink into it but when you get off the chair or sofa cushion it springs back to it's original height. However some people after their experience of fibre filled cushions prefer a firmer more supportive cushion and that is possible to achieve by using a firmer foam core. The heavyweight polyfibre wrap still gives the cushion the same puffed up appearance it had when it was new.
Fitting foam in to a cover can be quite difficult, here is a video showing you how we fit our new cushion inners in to customer's cover;