Policy on the illumination of collection material on display
Sensitivity of media The sensitivity of media to light and the subsequent fading of the colours in a collection item is one of the factors considered when establishing the acceptable amount of light exposure for a collection item. The use of the ISO rating, or Blue Wool (BW) Standard, enables a comparison of the fading that occurs to various types of media. BW 1 is the most responsive to light (meaning it fades the quickest); BW 2 is approximately half as responsive as BW1; and so on to BW 8 which is the least responsive. The media used in collections can be broadly grouped using their like...