I had (have) some pieces of what sounds like Dura-Skrim (matches
the description, anyway) that was sitting in a "take what you want
before we haul it away to the dump" pile of industrial debris (pallets,
etc) at an industrial site. I made a cold-frame one year of 2x4s with
a layer of that stuff inside and out. It is translucent, but seedlings inside
it grew as if they were not getting enough light (tall and sparse). It did
keep them from freezing, down to about 30F, with nothing more than
a light bulb inside.
It was around 4 feet tall, and I ended up converting it to a compost bin,
where the toughness of the Dura-Skrim came in handy and the low light
transmission was not an issue.
You can get stuff like this from Home Depot, Lowe's, Ace Hardware,
and so on:
http://www.homedepot.com/buy/paint/d...oll-54904.html
Light transmission probably varies from one brand to another, and it is
usually not UV-protected. (You can compare light transmission between
candidate coverings with a photographer's light meter.)
One would pay about the same amount for a 20 feet by 20 foot piece
of UV-shielded, non-woven greenhouse plastic. Light transmission usually
ranges from around 80-85% for woven and infrared reflecting non-woven
types up to what clear glass lets through for non-woven,
non-infrared-trapping products. The woven types are more resistant
to physical damage from wind, but they cost about twice as much per
foot and still only list a 4-yr lifetime (which seems to be determined
mainly by UV exposure).
6 mil greenhouse plastic is fairly stiff. It will last longer if you roll it when
not in use than if you fold it for storage (folds create stress points where
it will physically break down fastest).