In the upper and lower loopers. That's where its stretch and coverage do the most good — rolled hems, finished edges, and soft seams.

It stretches with the seam. On swimwear, lingerie, knits, and activewear, a non-stretch thread can snap when the fabric gives.

Yes. It fluffs out to fill the stitch, so edges finish smooth without a scratchy ridge.

1,000 meters — 1,100 yards.

Fifty.

Most sewists run it in the loopers only and use a standard polyester in the needles. That gives you stretch where it matters without losing seam control.