I just bought the fabric to have one made up tomorrow for the 12X20. Black interior, white exterior, Enclosed with elastic to grasp the camera back...open at the far end. Overall dimensions 90" X 60". About 1/3 the cost of the BTZS. Hope that it works out, but the price is right.
I would have taken Aggie up on her offer, but the lady at the fabric store offered to make it up for $10.00, I couldn't refuse...besides she was kinda cute, but probably no competition for our Aggie.