Before I presume to tell anybody how to set in a sleeve, a disclaimer: I don’t really know how to set in a sleeve.
Setting in a sleeve is one of those things that when I have to do it, I say to myself, What the hell, here goes nothing. I try to remember things I’ve been told about setting in sleeves. I do the best I can, and generally feel OK about it after it’s over. After all, I have a sweater! It has sleeves!
Do I Have to Do This?
When faced with setting in a sleeve, the first thing I do is ask: do I have to do this? If the sweater is knit flat, in pieces, and the sleeve is knit flat, the answer is no. You do not have to fit a tubular sleeve into an armhole. You join the shoulder seams, then mattress-stitch that sleeve head into the u-shape of the armhole, and THEN sew the sleeve seams and the side seams of the body. You do this with a traditional set-in sleeve in a flat-knit sweater, and you also do it for a raglan sleeve in a flat-knit sweater. There is some easing of fabric involved, but no big whoop.
A lot of the sweaters I’ve made were knit flat and in pieces. This method of construction has its pros and cons, but one thing it does not do is create tubes that have to be sewn into holes in other tubes.
My Monomania cardigan was not constructed in this manner. The body of the cardigan is knit flat, but not in pieces. It is knit in a single piece from the bottom hem up to the armhole openings.
Designer Ann Weaver took advantage of this construction method to do gentle shaping decreases and increases that are hidden within the chevron pattern under the arms. When you get to the armholes, you work the body and the two sleeves separately to shape the openings. Then you join the shoulder seams, creating two holes where the sleeves have to be sewn in. The sleeves, knitted in the round, are tubes. You have to sew (or otherwise connect) them into the holes.
It’s a three-dimensional proposition, sewing a tube into a hole. You can’t lie the pieces flat, so it’s hard to get purchase on them; they move. The challenge is to get the tube and the hole lined up—smooth and even, without bunching—then get them to sit still long enough to sew the seam. Over the years, I’ve tried regular sewing pins, safety pins, those wooden pins for knitting (the ones that look like tiny knitting needles), even hair clips. None of these tools were 100% satisfactory: the knitting always wants to slip and slide a little. Metal pins catch on the yarn, or split it.
Things started to get better when Ina Braun, a master knitter and teacher, told me about Clover Wonder Clips. Clover Wonder Clips are flat on one side, curved on the other, and they grip very tightly.
Step 1: Clip the center of the top of the sleeve to the center of the top of the tube, then clip the center of the bottom of the sleeve to the center of the bottom of the tube.
Step 2: Evenly distribute the rest of the sleeve around the rest of the hole, clipping as you go.
More clips, more better.
Step 3: Back-stitch or mattress stitch the lined-up edges of sleeve and hole together, removing the clips as you come to them.
I promise it is not hard. I will never quite feel like I know what I’m doing when I back-stitch a seam, especially a curved armhole seam. But I got it done, and it’s fine.