How to insert a zipper in a pullover sweater

Measure the center front of the sweater from the top edge of the neck to the end of the bottom seam, making sure the garment is lying flat, neither stretched nor gathered.

Cut a piece of lining that is 3-inches wide by the length of the center front of your sweater plus two inches. This lining is called the "sweater facing," which will finish the center front's future opening. Draw a chalk line, lengthwise down the center of the facing on the wrong (back) side of the fabric.

Fold the ends (top and bottom) of the facing one inch toward the wrong side of the fabric and crease with an iron. Fold each side of the facing one half inch toward the wrong side of the fabric and crease with the iron. The facing should now measure 2-inches wide and be equal in length to the center front measurement of your sweater.

Pin the right side of the facing to the right (outer) side of the sweater, lining up the center chalk line of the facing and the vertical center front of the sweater. The short ends of the facing--the top and bottom--should match the top edge of the sweater at the neck and bottom edge of the sweater at the waist or hip. Take special care not to stretch or gather the sweater knit as you pin. It must remain flat.

Stitch the facing to the sweater one quarter inch from the center facing chalk line on each side. Use a walking foot attachment to prevent stretching of the knit as you sew. Use a short stitch, like a 2 or 3, to prevent the knit from future unraveling. Back tack the starting and ending point of each sewing line.

Cut through the facing and the sweater front on the facing chalk line in between the two lines of stitching.

Fold the facing back to the wrong side of the sweater at the seam. Pin it in place and, with a needle and thread, hand stitch the facing down, using a blind hem. After the facing is secure, use a press cloth and iron the facing flat to crease and sharpen the cardigan edge, center front opening.

Prepare the zipper to the length of the sweater center front by removing the teeth beyond the appropriate measured length using a wire cutter. Transfer the lock crimps at the top end of the zipper to the new ending point using pliers. Leave at least one inch of the zipper fabric to extend beyond the new lock crimps position.

Overlap the cardigan edge, center front opening, with the zipper fabric on each side of the zipper about one-eighth of an inch away from the metal teeth. Pin the zipper in place and separate the zipper by carefully unzipping, without removing any pins. Fold the extra zipper fabric at the top ends toward the front of the sweater, trapping it between the zipper and the cardigan opening.

Stitch each side of zipper one-quarter inch away from the metal teeth or one-eighth inch away from the cardigan edge. Back tack at the starting and ending point of each sewing line. Remove the pins, trim the threads and zip the zipper.