The roller blind fabrics we provide, like all other reliable fabric suppliers in the upholstery/textiles industries, measure and test their fabrics against what is referred to as the 'Blue scale'. Fabrics are tested in terms of 'colourfastness to light' and the scale is 1–8. 8 is incredibly difficult to attain you won't discover fabrics in the window coverings marketplace that attain 8. The bl