I recently heard of something I will try next time. Instead of sewing the pieces together use a lightweight fusible interfacing! Overlap the two pieces and cut the joining line; remove the scrap pieces and fuse the interfacing over the join! I wouldn't try it on a polyester batting, but I'm definitely going to try it on cotton!
It's Not What You Gather, But What You Scatter
That Tells What Kind Of Life You Have Lived !
I butt my pieces together, but I use what is called a multiple zigzag stitch or tricot stitch (I have a Janome 6500, this is mode 1, stitch 9). It looks like a regular zigzag, but each zig is made of 2 or 3 short stitches. This keeps the batting from puckering.
Lay the two pieces down with the edges overlapping a couple inches . Cut through both edges at once in a gentle curve and get rid of the little edge pieces that are created. Then either loosely hand sew the curved edges that are butted up to each other or iron a strip of fusible interfacing over the seam to connect the two big pieces. I hope this is clear enough without any pictures. Karen
Lyndhurst, Ohio USA - East Side Suburb of Cleveland, Ohio