This International Standard specifies - a method for the determination of the gravimetric thickness of a Sample of plastics film or sheeting (see clause 3); - a method for the determination of the average gravimetric thickness and, if required, the yield (area per unit mass) of a roll of plastics film or sheeting (see clause 4). These methods are applicable to all plastics films and sheeting, and have special value when mechanical scanning is not sufficiently precise, particularly for measuring the thickness of embossed sheeting.