Restore the firmness or appeal of a sofa by ordering custom-cut foam and filler that replaces the undesirable material in the existing cushion. Stores such as Foam Factory, Direct Foam and Cushion Source create foam inserts that match the size, shape and flexibility specifications provided by the customer.
An additional option is purchasing a new, pre-filled cushion or seat to place directly on the sofa. Advantages to this option include the proper cutting and fitting of the material into the cushion casing and the possibility of selecting new decorative patterns and designs. Cushion Source sells replacement cushions and covers on its website, CushionSource.com.