From Michael Harding website:
Organic -My Quinacridone Gold is made from nickel azo and quinacridone. It is organic, transparent, with an average drying time, and possesses excellent lightfastness and high tint power. This is a rich, amber, golden yellow that is transparent and ideal for glazing or mixing to produce interesting hues. Its shift from mass tone to undertone is very pronounced with a rich very transparent orange-brown in mass tone through to brighter yellow golden undertones when glazed.
I have been very patiently waiting for the right moment to reveal this new oil colour. It’s beautiful, perfect in every way, particularly for artists who like either glazing or just having a crazy time with colour. You might find yourself in rehab to cure your addiction to it. Perhaps I should put a health warning on my tube Quinacridone Gold: Danger! Addictive! I, myself am particularly fond of Quinacridone Gold. I often wonder what the Old Masters would have thought of the new, marvellous colours that we have today. Specifically, if I could go back in time and ask Mr Turner what he would have thought of Quinacridone Gold. I would enjoy seeing how he could have used Quinacridone Gold in “The Fighting Temeraire” or one of his other glowing skies.