Remember that 100% figure I told you to write down and not lose? The one that is the total number of stitches (minus the steek) that you cast on to knit the body of your jacket? Go find it. And if percentages give you a headache, get a calculator (there's one in 'accessories' on Windows running computers, if you don't have one handy).
All right. To find out how many stitches to cast on for your sleeve, you want 20% of your body stitches. For example, my 100% figure is 227.
227 x 20% = 45.
So I cast on 45 stitches for my sleeve cuff. Got the idea?
Okay. For casting on, you are going to copy the hem on the body of your jacket, except that you'll knit it in the round. So do a provisional cast-on of some kind, join (without twisting), and knit the same type of hem as you did on the body. Mine was pink, eleven rows deep. So that's what I did again. Then I knit one round of blue, purled one round of blue (for the fold line), knit another round of blue, and then started on the pattern.
To center the pattern, first establish an underarm stitch or two (this would be the seam, if it were knit flat). If you have an even number of stitches in your sleeve, use one underarm stitch. If you have an odd number of stitches, use two underarm stitches. (There are math-related reasons for this. If you wanna know, e-mail me, but I don't wanna confuse the heck out of everyone.) All right. Find the center stitch, across the sleeve from the underarm 'seam stitches'. Then count backward from the center stitch, back to the underarm 'seam stitches' to figure out where in the pattern to start.
The original graph, which we all printed out, is set up so that the LAST stitch of the pattern, the vertical line, can be used as a center stitch. Count backward from there along the graph to figure out where to start your sleeve. If you do it right, you should have a mirror image on either side of the underarm 'seam' stitches:
With me so far? (If not, e-mail me, as always. Ask Bells and Louiz, I'm always happy to help. Really. And I'd like to think I AM helpful. Even if I did make fun of Bells' math skills.) And incidentally, in the picture I'm using two underarm seam stitches.
Increase one stitch on each side of the underarm seam (that's two stitches total) every fourth round. Increase until you get 40% of your total stitches figure. Again for example, mine:
227 x 40% = 91
So I increased until I had 91 stitches, then knit straight with no more increasing until the sleeve was as long as I wanted. (Six pattern repeats, for what it's worth; yours will be different because it's a different gauge and you don't have long, gangling, simian arms.) Keep in mind, if you start with an odd number, you'll have to finish with an odd number, and ditto for even numbers. If, between 20% and 40% you get an odd and an even number, round one up or down to make them both odd or even. One stitch won't make any difference; remember. It's kntiting. It stretches.
Do NOT freak yourself out, doing the increases 'in pattern'. Just look at the chart, look at where you are in your knitting, and figure out if you should make a stitch with your light or dark color, do so, and knit on. It's not brain surgery. Remain calm. Do not freak out. That is an order.
To end, END ON THE SAME PATTERN ROW YOU ENDED THE BODY WITH. I think I told everyone to end the body on the last pattern line, line 14. So end your sleeves on line 14, too. Honestly, you can end it on ANY row, BUT END THE SLEEVES AND THE BODY ON THE SAME PATTERN ROW. If you don't, when you join them up, you'll have to shift pattern rows between body and sleeve as you knit around the sweater and drive yourself insane. (Plus the pattern will jog weirdly when you look at it in it's finished state, but that's minor compared to driving yourself crazy.)
All rightie then, go for it!
I'm only on the hem of my second sleeve, myself, so I'm not much ahead of you guys. You're FAST!