Lightweight & Stretchy Sweater Knits
Sweater knits are what I like to call "instant" sewing; the pattern pieces are generally simple, the fabric is easy to sew, and the projects usually are fast to complete! There are so many varieties of sweater knits from which to choose. This particular knit category is for those that have 2 way stretch and are light to medium weight. You'll be surprised at the ease of sewing when you try these knits. Your garments will look much more difficult than they really are, simply because of the knit details.
Treat the fabric as you would treat a sweater. Machine washing may cause the fabric to shrink; test a sample to check. Hand-washing, and laying the garment flat to dry, are the safest options.
Use a 80/12 stretch needle for your seams. Poly/cotton thread or all polyester thread are the best choices for working with this fabric.
Should your project require interfacing, choose a lightweight interfacing like So Sheer or Fusi-Knit. If your sweater knit is textured, place a terrycloth towel on the ironing board, then place your fabric face down on the towel before fusing. This will prevent the texture from crushing. Match the grain of your interfacing to the grain of the knit.
Choose a medium width zigzag stitch, 2.0 length, 2.0 width, in order to work with the stretch of the fabric. If you have a serger, a 3 thread overlock with balanced tension will work beautifully. Most sweater knits will require a seam finish of some sort. If you have a serger, use a 2 or 3 thread stitch on the edge of the fabric. If you do not own a serger, use a 2.0L, 3.5 W zigzag stitch over the edge before construction. Press the fabric after using the zigzag edging to ease in any possible distortion that is caused from the stitching (steam will take care of this!). A twin-needle hem is not necessary in this knit. In fact, the stitching will be lost in the texture! Save your twin needles for other projects. Simple clean-finish the edge of your fabric, turn under the hem, and zigzag the hem in place. A flat-lock hem on your serger works well, also.
choose a pattern for knits that is listed for "moderate stretch". Take your cue from ready-to-wear sweaters. If the pattern looks like a sweater or sweater coat, you're probably on the right track. Avoid horizontal darts, intricate pattern pieces, patterns with very small inserts, and items which are very body-conscious. You can, however, use these knits for tailored items if you use a thinner fabric for the underlayer of collars and cuffs (see additional tips for specifics).
Test making buttonholes on a scrap of your fabric before sewing on your garment. Begin by stabilizing the area under the buttonhole with interfacing. For most sweater knits, the same interfacing you use for the rest of the garment is the best choice for the buttonhole area. Use a more "open" satin stitch for the buttonholes by adjusting the length of the stitching. Cord the buttonholes by inserting a few strands of the fabric threads under the presser foot while stitching the buttonhole. Covered large snaps make excellent, elegant closures on sweater knits. Purchase large snaps, ½ inch wide or larger, and cover them with thin coordinating fabric. Zippers are not good choices for closures on most stretchy sweater knits.
Use a fun yarn as trim for your sweater knit. First, run a row of wide zigzag stitches parallel to the cut edge of your fabric for stability and to prevent ravelling. Using an "eyelash" type yarn, crochet two rows of single crochet stitches catching the fabric and the zigzag stitches. Don't crochet? Lay three strands of the yarn ¼ inch from the edge of the fabric and use a blind hem stitch or wide zigzag stitch to secure the yarn. Sweater knits pair well with suede, stretch wovens, velvets (stretch and standard velvets), and fold-over braids.
Occasionally, you may need to weight the hem of a sweater-knit garment to allow it to hang properly. There are two excellent methods for weighting your hem. First, you can pad the hem slightly with interfacing or a bias-cut layer of soft fabric like flannel. Baste this layer of interfacing or flannel into the hem allowance before stitching your hem. The second option is to hem your garment with a facing and add a decorative chain 1 inch from the fold of the hem on the inside of the garment. This second option is particularly elegant for jackets and cardigans. Should you choose to make a tailored sweater-jacket with this fabric, be sure to consider the following: 1. Choose a lightweight knit or bias-cut woven for the undersides of collars, lapels, cuffs, and hems to reduce bulk. 2. An underlining of mesh knit, tricot, or stretch woven will add to the longevity of your garment. 3. Use a slightly heavier weight interfacing for the shoulder of a tailored jacket in the knit. I like Whisper Weft for this application. Cover the interfacing with a half-lining. 4. For an up-to-date ready-to-wear type sweater jacket, use velvet for the collar, cuffs, and the lapel. It's a beautiful combination!