To decrease for the top of a hat in two-color brioche knitting, the simplest decrease is worked over three rounds and is called the br-ssk (brioche-slip, slip, knit).
To perform the decrease, you’ll need to learn these abbreviations:
wyif – with yarn in front
sl 2 yo – slip the next two stitches, one after the other, then wrap the yarn around to the back like a regular yarnover. You will have two slipped stitches accompanied by a wrap.
To decrease in two-color brioche in the round:
Round 1: Work in brioche up to 2 sts before the stitch you want to decrease (you can place a marker on this stitch, if that helps). Slip the next st knitwise, twice. Br-k the next st (the marked st). You will have two same-color sts next to each other. Work in brioche to end of rnd.
Round 2: Work in brioche up to the two same-color sts next to each other. Wyif, sl 2 yo. Work in brioche to end of rnd.
Round 3: Work in brioche up to the two slipped stitches. Br-k the two slipped sts together with their wrap. Work in brioche to end of rnd.
To knit a two-color brioche-stitch scarf, you’ll need to use a needle that has two ends, because you’ll have to slide your work from one end of the needle to the other, to repeat the row with the other color. Either twp double-pointed needles or a circular needle will work, although two DPNs (double-pointed needles) will be easier because there is no cable to get in the way of what you are doing.
Practice on the following swatch. Note that you are going to cast on an odd number of stitches, and work each edge stitch as a selvedge stitch, so that the edges are even. Again, we designate LC as “light color” and DC as “dark color.”
Two-color brioche knitting – flat:
Using both DPNs held together (this makes the cast-on looser) and with DC, CO an odd number of sts (e.g. 13 sts). Remove one DPN. Turn.
DC set-up row: with DC, (p1, yf sl1yo) to last st, end p1.
Do not turn work. Slide sts to other end of needle.
LC set-up row: sl 1, with LC (br-k1, yf sl1yo) to last st, sl 1 wyif. Turn.
Row 1: with DC, k1, (yf sl1yo, br-k1) to last 2 sts, yf sl1yo, k1. Do not turn. Slide sts to other end of needle.
Row 2: sl 1, with LC (br-p1, yf sl1yo) to last st, sl 1 wyib. Turn. Row 3: with DC, p1, (yf sl1yo, br-p1) to last st, end p1.
Do not turn. Slide sts to other end of needle.
Row 4: sl 1, with LC (br-k1, yf sl1yo) to last st, s 1 wyif. Turn.
Repeat rows 1-4 until you are ready to bind off. Using DC, BO using any stretchy bind-off.
Now you can make a gorgeous two-color reversible brioche scarf. Try this with different types and combinations of yarn – thin yarn on larger needles will give you a light, ethereal effect.