I save most pieces. I use the very lightweight Pellon fusible interfacing in place of Heat Press to fuse the strips/pieces together. However, I also zig-zag on the reverse side of the batting at the join. Heat Press is so expensive & I'm trying to save money. I'll buy 5 yards of the interfacing at Hobby Lobby with the 40% coupon, so it becomes economical. I then cut it into 1" wide x width strips. I also fuse it up as soon as I finish trimming the quilt. I make the piece as big as I need it to be. I do save the batting in the original bags so I know what batting I'm using as sometimes I forget!