acoustic vertical window blinds


Does anyone have  recommendations for manufacturers or suppliers of room blackening/darkening vertical window blinds for use in my mostly audio room? On each equal length side of each speaker ( a bit over 6' ) there are windows, on one side a standard double hung, on the other a rather large 4 panel bow window (over looking a fairly lovely private natural setting). I may or may not stay in this house for very long, so I neither want to overinvest nor shortchange my listening pleasure. I need to replace the current vertical blinds, and thought my fellow Audiogoner's might have some suitable suggestions.

Thanks in advance.

unsound
I have three windows behind my speakers and a patio door on the opposing wall. Last year I installed Hunter-Douglas Cadence Vertical blinds and I used to have acoustic panels on the walls and have not put them back up. These blinds when you look at each vane From the end have a S shape to them. They are fabric but very stiff to retain that shape. You may want to look at those they show them on the Hunter Douglas website.
One solution that will work better than any blinds or shades is to attach a number of ASC or GIK absorber/diffusers (like the ASC sound planks) using Velcro tape. This will be fully removable when you leave and you can also take it with you. Finally adding a Marigo VTS window dot to the glass will also help