Thanks. I do use Sunfilm. My supplier says he has never sold the black as most of the wrap used by local dairy farmers is to fully wrap sileage bales. He would get it for me - if I take a pallet load... 

I will try to find someone who stocks the black Sunfilm, if you feel it is worth the effort.  I did try the sleeves which are black.

The Sunfilm appears to be a very good product.

Jim at Dawn