In article , Tim Tyler writes

Not a difference that matters - since UV-inhibited polythene works by
inhibiting UV light. From what I can tell, it prevents it from
damaging the polythene by reflecting most of the incident UV
radiation back.

According to Northern Polytunnels catalogue, all their three grades of
UVI/EVA polythene provide a light transmission of 90 percent. Thus 10
percent of Ultraviolet and other rays are inhibited by the inhibiting
properties of the material. To suggest otherwise would be misleading.
--
Alan & Joan Gould - North Lincs.