What tips or advice can you give me for working with lycra? -Sara, Montgomery
You won't need special presser feet for sewing Lycra blends, but a good-quality, all-purpose polyester thread is your best bet because the thread itself has some stretch built in. When threading the bobbin, be sure not to wind it too fast, or the thread will be stretched and the seams puckered. Resist the urge to stretch seams as you sew; using a narrow zigzag (of the lengths specified below for knits or woven's) will add all the stretch your seams need.
For sewing nylon-Lycra knits, use a 70/10 ballpoint needle; for all other Lycra-blend knits, a 75/11 HS stretch needle is appropriate. Areas of stress, like crotch and underarm seams, need a 2.5mm triple stitch ; other seams, such as those at side, inner leg, and casings, take a narrow, .05mm- to 1.5mm-long zigzag. Test seams after sewing by stretching as much as possible. If stitches break, loosen the top thread tension, and test again until there's no breakage.