SDC Light Fastness Fabrics, For Household, Industrial, Laboratory

SDC Light Fastness Standards 1 to 8
These are a series of 8 wool fabrics dyed with specified blue dyes to give blue wool cloths ranging from very low light fastness to very high light fastness. This forms a numerical scale of 1 to 8 where 1 has the poorest light fastness, to 8 which has the best light fastness.
SDC Humidity Control Fabric
This is an azoic dyed cotton fabric with specified fading properties, which varies with the amount of relative humidity.
It is used as a calibration tool for light fastness testing.