Matthews manufactures 6.1 m x 6.1 m (20' x 20') Overheads with the best fabric available on the market today. Please consult our fabric specifications page for a quick overview of the usefulness of each fabric. Matthews 6.1 m x 6.1 m (20' x 20') are sized to the industry's approximate standard measurement of 5.94 m x 5.94 m (19'6" x 19'6"). All fabrics are tested in a black room with an incandescent light source at one end and the fabric positioned 2/3 of the distance between the source and the digital lux meter.