I do not know the answer to your question but I do have an additional caution - my company has experienced a higher rate of failure of certain materials in the Colorado area than in most other places. Specifically, this was neoprene synthetic rubber which developed cracks within about 1 year as opposed to 4 or 5 years in other places. Our suspicion is higher levels of certain pollutants in the atmosphere there. I am just warning you because I would suggest that you need to check on the resistance of your plastic to aerial pollutants (as well as UV) in your air if you expect it to last several years outdoors. Sean On Thu, Dec 29, 2011 at 3:22 PM, YES NOPE9 wrote: > If a roll of 6 mil black plastic does not say it is UV resistant ....... > Does one presume it is not ? =A0 =A0If it does say it is UV resistant, > what kind of lifetime will it have in Denver, CO ? =A0( sunny most days ,= high altitude ) > 99guspuppet > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .