You must know what the stretch is and how much stretch the fabric has in order to work with a pattern designed for knit fabrics. The information you need is on the pattern envelope. There is usually a graphic that will say X" of fabric must stretch to X". It also will state if the stretch needs to be one way or two way. You also must pay attention to the direction of the stretch in laying out pattern pieces. These are important factors in having the sewn item fit properly. If your sewing machine offers many stitch options, refer to your sewing machine manual to find the best stretch stitch options. It is well worth your time to learn about all the stitch options you have because many of the stitches can be used for more than one process. Another important aspect of sewing knits is finishing all of your seams with a seam finish which stabilizes the seam and prevents the seam allowance from curling. As with all seam allowances, you want the seam allowance to lay smooth and blend into the garment rather than be a lumpy eyesore.
