Lexan Thermoclear 20 year 8 & 16mm have outside surface UV Protected, anti-condensate on inside surface.
16mm X-Wall, 25mm X-Wall & 25mm 3-Wall have both sides UV Protected Opal is white
Thermoclear “20 yr” Yellowing resistance. 2% change in 10 yrs. *** 20 Year Warranty ***.
25mm X-Wall Thermoclear Plus Yellowing also 2% change in 10 yrs. Typical Service life 20+ years.
Regular Lexan ThermoClear changes 6% in 10 yrs. Typical Service Life 12 years.
The less the change in clarity, the longer the sheet service life.
Yl is yellowing index, low number = less yellowing (aging), number 5 = 4% change in light transmission.