Blue Scales (Blue Wool Fade Cards) – #BWFC



These cards, which measure 5″ x 1.5″, feature eight strips of wool cloth dyed in different degrees of color-fastness. They are used by conservators and curators to measure intensity of the illumination a display is exposed to and to alert them to reduce the level of lighting or rotate an exhibit. Ideally, one card should be kept in darkness and compared to a second card kept in the display case in order to measure the progression of light damage.