This had come up a few years ago, and I beleive it was Karen Wells who had a great solution that I followed up on.
There is a product called "Photek Background-in-a-bag". It is a background and support bars all in a portable bag. The backdrop comes in different colors and also you can choose between 8x12 and 6x7. The whole system is lightweight and very easy to put together and take apart which makes it great for going on the road.
The backdrop itself is soft velour and a nice weight similar to a blanket weight. Because of the weight it hangs nicely and no light comes through. The backdrops are solid on one side and a painted effect on the other. I purchased the gray backdrop, and if I want different colors I can pin a table cloth, sheet, blanket or whatever right to the gray backdrop. That way I have the support system and nice cloth weight of the purchased set with the color changes at will.
I purchased mine from
www.adorama.com. The prices are $109.95 and $159.95 depending on the size chosen. Their navigation system doesn't make their location readily apparent so I recommend putting "Photek Background-in-a-bag" in the search box.
Hope this helps.
Mary