Used as light fastness standards, to monitor the net exposure to light of art objects on display, and to alert conservators to rotate an exhibit or to reduce the intensity of illumination.
Eight pieces of wool cloth tinted with blue dyes of different degrees of fastness mounted on a 5"x1 1/2" card. These cards conform to the ISO 105-b01 standard. Please note: There are two cards pictured above, the one on the left represents a "control" card that is stored in total darkness. The one on the right, (displayed here for contrast only) has been exposed to UV light and has faded.