Howard is correct!
The colours are vibrant and so far it has proved to be UV fast. Mind you we don't get your hot sun in the UK! I always cover with the very thin mylar that the free flight guys use. It takes a bit of practice but worthwhile as you don't need much dope to seal the silk. It produces a very light and strong covering and looks good with the Dharma dye. Not concourse, but very old time authentic looking!
Andrew.