I butt it hand sew with a large ladder stitch, can never tell when quilted. I have pieced batting for a large quilt before and will be doing it more.

I just did the same thing! I did buy the iron on stuff and just got it will try it soon. Isn't great to be able to not Waste?!

I either butt the ends and zigzag together or whipstitch them. I don't notice where the edges are after I get the quilting done.

I have quilted the quilt with the joined batting and I really can not tell where it is. I am pleased I tried this, this means I can actually buy less, since it is so wide and cut and sew to make the size. This quilt is more a lap size, but none the less I only used a metre of purchased batting. Thanks to all you fellow quilters who have written about this in the past.