If you're working with a lot of stretchy fabrics and/or fabrics that will ravel easily a serger is seen as a better choice by many folks. A serger will "finish" the seams as you sew them. Where a regular machines just puts in the stitch you select - generally a straight stitch for a seam, the serger will put in the straigth stitch, bind the edges and cut off the excess seam allowance as you go.
Take a look a the seam in a commercially made garment. Many of them look like they have a tight zig zag sort of stitch along the edge of the seam. That is a serged machine.
Having said all that there is a definite down side to using a serger - it is MUCH harder to undo mistakes or refit something. It essentially has to be perfect the first time.
I do a LOT of sewing and although I've tried them I simply don't like working with a serger. On those occasions where a seam absolutely must be finished I finish it. And I have also worked on plenty of stretchy materials - it is a matter of setting the tensions properly, using the correct needle, and stretching the fabric carefully as you go so there is stretch in the stitching.
Deb
