They have 108" "mottled black" at Bear's Quilt Shop here in CA.
http://www.bearsquiltshop.com/pages/ucCart/product.asp?reckey=5093
Their fabric is NICE too. You might email them & ask if they have plain black if this one won't work (or you can't find one closer to home!). I got a beautiful deep claret red backing from them a month or so ago.