Full Description 1. Purpose and Scope
1.1 This test method is intended to spectrophotometrically measure the light blocking properties of window covering textiles against light passing through them and being seen by a standard observer on the darkened side of the textile (typically a curtain or drape.)
1.2 This method is applicable to all types of fabrics, including knits, wovens, and non-wovens, as well as to fabrics taken from end product items. However, it is not recommended for mesh structures with mesh holes greater than 3 mm across.