Has anyone ever zigzagged pieces of this together for a quilt? I do it all the time with warm and natural but not sure with this because it is so fluffy. Will it "sink in" where you combine it?

if you have a very lofty one-yes it will sink where you zigzag them- prehaps you could use that new batting tape that has hit the market that would keep it from being mushed by your zigzagging.

When piecing poly batting I do a large zigzag stitch by hand. It just takes a few minutes, does compress the batting, and only needs to hold together until it is quilted. I'm not sure about using the tape on poly. I would be afraid the iron would melt the poly unless the tape works with cooler temps.

When piecing poly batting I do a large zigzag stitch by hand. It just takes a few minutes, doesn't compress the batting, and only needs to hold together until it is quilted. I'm not sure about using the tape on poly. I would be afraid the iron would melt the poly unless the tape works with cooler temps.

About how far apart do you put the zigs and the zags? Can I make it faster by spreading it out?

I use Polydown all the time and I have often zig-zagged pieces together on my machine. I just use the biggest widest setting on my Janome 6500. I often make brightly coloured scrap quilts that are always machine quilted and you just don't notice the batting joins.

I also zig zag with a very large stitch by hand as well as by machine and it has never matted down. But then again, I always use low loft.

This what I do with lofty poly batting. And I don't like the tape.