Specifies the determination of loss in thickness and loss in hardness of materials intended for use in upholstery. Provides a means of assessing the service performance. The method is applicable both to standard size test pieces cut from stock material and to shaped components. Formulas are given to express the loss in thickness and the loss in hardness. Two figures show the details of a manually adjusted machine and an automatically adjusted. Constitutes a minor revision of the second edition (ISO 3385:1982).