Quote Originally Posted by tongue_tied View Post
Do you actually have to specific to the alterer that you need the serger stitch - the stretchy, interlock stitch?
Yes. Otherwise the stitches won't stretch and the threads will break. OR, if you stretch out the fabric while stitching, then it doesn't lay flat - it's all rumply. But you definitely need a stitch that will stretch, and regular zigzag doesn't do it enough. And picking that out is no fun at all.

Most alterations shops have both regular sewing machines (traditional) and serger machines, so it shouldn't be a problem to find a shop that can do this for you.