Expert: Sarah - 5/27/2009

Question
i AM SEWING SPANDEX MATERIAL (WITH COTTON LINING).  AM USING A ZIGZAG (#4 STITCH).  SEAM DOES NOT LAY FLAT - KEEPS STRETCHING AS I SEW.  
AM USING A POYYESTER THREAD AS SUGGESTED BY STORE WHERE I BOUGHT THE MATERIAL.  HOW CAN I GET THE SEAM TO LAY FLAT?

Answer
Hi Ruth,

The first thing that comes to mind is that you are using too many stitches per inch. You can try increasing your stitch width, to increase the distance between stitches. The less stitches there are, the less disturbed the fabric will be.

Also, be sure you're not holding the fabric as it is sewn. This can be very subtle, but if you're stretching at all, it will start to ripple very quickly! The way the machine pushes the fabric through, it is very easy to sew along and not notice.  Ideally, you want the fabric to run through the machine effortlessly. All you want to be doing is guiding it through so it doesn't go off course. Don't hold it down, and don't pull it out at the other end.

With the materials you're using, I would advise using a clear or knitted elastic tape while sewing - depending on what you're making. Set the elastic on top of the two layers, sew the seam through all layers, but while sewing pull on the elastic just a LITTLE BIT! Keep an even tension on the elastic the entire way through. In situations when knit material won't behave, clear elastic tape can give you the tension control you need.

Last, I can't tell you how much of a difference a good ironing can have on the look of a finished garment - even on spandex! Press the seam well.

Hope this helps. :)

~ Sarah