Humidity Control Fabric to meet ISO/BS standards, 1 piece 250mm (10”) X 150mm (6”),

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.

When the humidity of the light fastness testing machine is correctly set it will fade at an identical rate to the light fastness standard Number 5.