These have been tested and results compared to the RDN 1X2. They used polystyrene from DOW and from a Japanese company. Kuraray says that the DOW PS is better than what they can get from their Japanese supplier. Japanese PS .8 to .85 K,Chroma '98 . Humidity has no effect on the aging.
Temperature cycling has some affect on the light yeild.
These pieces are from the Quick 1997 run.