Work to where you want the buttonhole to begin, bring yarn to front, sl 1 pwise, bring yarn to back (Figure 1).
*Sl 1 pwise, pass first slipped st over second; rep from * 1 (2, 3, 4) more times.
Place last st back on left needle (Figure 2), turn. CO 3 (4, 5, 6) st as follows: *Insert right needle between the first and second sts on left needle, draw up a loop, and place it on the left needle (Figure 3); rep from * 2 (3, 4, 5) more times, turn.
Bring yarn to back, slip first st of left needle onto right needle and pass last CO st over it (Figure 4), work to end of row.