i cut my own extension out of 1/4" plywood and 2 x 4 blocks for legs... then i covered the sewing machine AND extension with plain old oilcloth. i taped it down around the hole i cut for the foot (about 3" square) with duct tape as it comes off pretty easily... i only tried it because i wanted a bigger extension than those available... mine is 4 ft from right hand side of sewing machine to left hand corner, and 3 ft deep as that was all the bigger my table was. this has made it a lot easier to move around and all i have to do is re-tape occastionally... it usually lasts thru 3 or 4 quilts before it has too many 'fuzzies' on the edge of the tape to affect it...