… what goes on under the arms.
First: a few comments on basic human morphology.
Most of us, when viewed from above, and relative to our shape at chest-level, are not based on ideal geometry, neither circular:
nor designed like an old-fashioned letterbox with knobs:
Most of us are, as the shape below (which was roughly traced from an MRI scan of chest and arms) shows, somewhat wobbly, lumpy, and slightly asymmetrical:
The key thing to recognize is that our arms are not simply “stuck” onto the rest of us at the edges, regardless (or irregardless as the case may be) of proportion and size. We are indeed a miraculous whole, all of a piece, and there’s a front-to-back “depth” dimension where our arms attach to our trunk (that which is often rudely called the “armpit.”)
Knitting patterns ignoring the armpit dimension dismiss it at their peril.
Now we’ve got that out of the way, let’s talk about top-down patterns. I’m a big fan. They are usually done on circular needles, they start at the neck and, in their simplest form, they increase the number of stitches, usually in alternate rows, as you go round and round (for a sweater), or back and forth (for a cardigan) in a way that’s similar to raglan shaping, at four points across each round or row. More estoteric patterns shape a yoke, and/or may include color-work, or short-row or other techniques to create a lower neckline at the front, or more depth in the back, for better fit. Sometimes, it’s a bit baffling as to how this will work, but if you follow the pattern, usually it does.
(Parenthetically–which is why this remark is in parentheses–this explains one of my biggest disappointments ever in top-down knitting.)
To continue: Once you’ve done enough rounds/rows to get to the armpit, you begin a new one (imagining that each row starts at one side of the back) on which you knit across the back stitches and then thread the “arm” stitches of the first arm you come to (in this case the left, if you’re a right-handed knitter) onto a piece of waste yarn, just for the time-being. You then cast on a specified number of stitches which we will think of, for the purposes of this discussion as the ARMPIT STITCHES (apologies for the vulgarity). Then you knit across the front of the sweater, put the “right arm stitches” onto a piece of waste yarn to hold them for the time being, and cast on the same number of stitches as you did before, this time for the RIGHT ARMPIT.
At this point, your “arm stitches” are all held on two pieces of waste yarn, one at the left and one at the right, and you’ve connected up the front and back of your sweater/cardigan with ARMPIT STITCHES of the number specified in the pattern, on either side. And now you keep going in rounds or rows, until you get to the waist, or wherever you are going next. (Usually it’s to the waist, and then there is a bit of ribbing, and you cast off, and you’re done with that part.)
To finish the sweater, you go back to the arm stitches on the waste yarn, pick up the first set, then pick up across the ARMPIT stitches to create a round, and knit down that arm, following the shaping instructions given in the pattern until you get to the wrist. Then follow the instructions to finish. Ditto, on the other side.
Usually, if you are knitting a pullover, you’re done at this point. For a cardigan, follow the instructions for the welt and buttonholes. Then, done!
I like this method because there’s very little assembly and stitching together at the end of it. Also, the pattern is usually pretty easy to follow.
So, back to that remark I made a few paragraphs ago about disappointment:
Many (many) years ago, I started out to knit myself a top-down sweater that was featured on the cover of one or another of the Vogue knitting magazines (I’ve since thrown the magazine out, for reasons that may become clear as we proceed, so I can’t point to it specifically). It looked like a beautiful sweater, had some colorwork in the yoke, and was knit in a mohair blend, so wonderfully soft and fuzzy. I bought the magazine, bought the exact yarn, and got to work! I followed the instructions exactly, as there was some of that “short row” shaping business to start with, and I wanted to get it right.
I finished it. Got to the wrists on both sleeves, with a bit more colorwork above the ribbing. Finished the ribbing. Done!
I tried it on before I blocked it.
And, huge disappointment.
The fit was awful. Something very nasty was going on at the armpit level. I checked the pattern. I’d followed the pattern exactly. But it was pulling, was uncomfortable, and looked dreadful.
I eventually determined that the person who designed the pattern was working off the “letterbox” principle. As if I had dimension across my front and back, but very little dimension from one side of my armpit to the other. As if I was some plywood cut-out, only about one-inch thick from front to back, like those in a theme park where you can get your photo taken “standing next to” Doc Holliday or Wyatt Earp.
What I discovered was the the ARMPIT stitches I’d added in, per the pattern, were far too few (six, IIRC) to actually make a comfortable fit, and so the sleeve itself was pulling in, front and back, into my armpit, to try to make up the difference. Very uncomfortable. Very ugly.
I couldn’t bring myself to rip the body and the sleeves back and start over from the armpit (this is one of the hazards of the top-down method–a mistake like this is costly), and so I gave the sweater to charity (hope someone found it worthy) and moved on.
But I’ve never made that mistake again.
Top-down knitting patterns that have never let me down come from Knitting Pure and Simple. (No, I haven’t contacted them, and no, they’re not paying me. This is just your Voice of Experience speaking). They always fit well, especially under the arms. At the moment I’m knitting this one: V-Neck Cardigan, which is of a similar gauge to my “disaster sweater” and which has, for my size, 16 armpit stitches on either side. And that (10 stitches on either side) is the difference between a comfortable fit and a knitting catastrophe.
I’m not suggesting that you abandon patterns you’re smitten with that may contain an “underarm fail.” One of the nice things about the top-down method is that there isn’t any penalty for adding a few stitches across the armpit dimension to make things more comfortable. I’ve done it myself, and you can do it too! Just remember, when you get to the “picking up the arm stitches” business, to knit up the same number of stitches across each sleeve that you cast on for the underarm for the body.
Penultimate tip from your VoE: It doesn’t matter what method you use to cast on those stitches. I almost always use the “cable cast on” method. When I want a loose cast on (as for the armpit stitches), I just knit into the “front loop” of the preceding stitch. When I want a firmer edge, I put my right needle in between the two previous stitches (as is shown in the video). Either way, it’s the technique I first learned, and the technique I teach in my knitting classes (not least because I’m lazy, and because once I’ve taught it, my students already know how to knit. Another reason is that, no matter how many yards or miles I allow for the vaunted “long-tail” cast on, there never seem to be quite enough . . . so screw it.) That’s just me.
And last tip: I cast on two more ARMPIT STITCHES than specified on the row/round in which I create them. Then, on the next row, I knit two stitches together, one from the ‘front/back’ group of stitches, and one from the ARMPIT STITCHES. This returns me to the correct number, and closes up any looseness in the stitches, which is sometimes unavoidable from the cast-on and joining-up.
So there, my peeps, you have it.