Separating Zipper Tutorial: Handsewing a zipper into a handknit sweater

I love a separating zipper in sweater to make it feel more like a jacket. They're also great in children's sweaters like the photo at left taken by Chris Hartlove for Interweave Knits. Once you have mastered putting one in once, you’ll turn again and again to this technique. A month or so ago, I promised a lesson so that when you finished this adult sweater from the Fall 2006 Issue and this child's sweater (shown left) from the pages of the spring 2006 issue of Interweave Knits, you wouldn’t be afraid to really finish it.

Unfortunately, separating zippers don’t come in as many colors as regular zippers. I always make a run to the fabric store before deciding on the color of the yarn I am going to use. I want my zipper to match the sweater (although you could do something completely fun and have a contrasting zipper). You can always feel pretty safe with navy, black, dark brown and red – these colors are normal outerwear colors and separating zippers sold in fabric stores are usually sold to replace broken ones store-bought outerwear. (….unless people don’t do that anymore – they just throw the coats away – I digress….)

Finish the entire sweater, including weaving in ends, washing and blocking. I REPEAT, INCLUDING WASHING AND BLOCKING! Measure the opening and purchase a zipper. Do not purchase a zipper any shorter than the opening – if anything 4 or 5 inches long is better.

Lay down the finished sweater on a flat surface. Lay the zipper between the two open edges. With straight sewing pins, pin the sweater at the top and the bottom of the zipper on both sides. The top of the zipper may extend beyond the sweater pieces – that’s okay. Do not stretch the knitted edge as you are pinning or the edge of the sweater will flare and be longer at the zipper insertion point than around the rest of the sweater – a totally unsightly problem - if I may say so. Pin along the sides of the zipper so that the edges are about 3/8” away from the center of the zipper teeth.


Using a sewing needle and a single strand of matching sewing thread (to the yarn, not the zipper if you are inserting a contrast color zipper), beginning at the bottom edge, sew the zipper by hand using backstitch. Many separating zippers begin with a plastic tab which is difficult to stitch through but not impossible. A thimble can be helpful. As you go, stitch over the individual yarn and stitches to anchor them in place. Remove the pins as you go. The backside of your sewing (the zipper side) will not look neat – don’t worry. The idea is to have your zipper securely attached to the knitted fabric. You’ll notice that the sewing stitches disappear into the knitted fabric. Keep stitching the zipper so the knitted opening is an even distance from the zipper teeth. Continue until you are at the top of the zipper but do not worry about the length of the zipper just yet.

Finish the other side the same. Now turn the sweater inside out.

Unzip the zipper until it is at the tippy top of the sweater opening (where it should end). Turn down the top of the zipper so that the zipper tails form a slight angle away from the pull. Pin in place.

Using a single strand of matching sewing thread, tack down each zipper tail neatly until you have attached about 1” of the zipper to the back of the sweater/zipper. Snip off the zipper leaving about it 1” long. Continue to tack around all edges of the zipper. This will keep the pull on the zipper track.

You did it. Eat your heart out Mr. Rodgers!

P.S. If you have found this tutorial helpful, please spread the word. I'd love some more traffic on this blog! Thanks - KN