Small adult/large child: 19"/48cm around band.
Medium adult: 21"/53cm around band.

1 skein Koigu KPPPM (175 yds/160m); shown in Color 830.
Or 175 yds/160m of an equivalent fingering-weight yarn.

US 2 (2.75mm) 16"/40cm circular and double-points, or size to obtain gauge.
US 1 (2.25mm) 16"/40cm circular, or 1 size smaller than gauge size.
US 10 (1.15mm) steel crochet hook for placing beads.
1–2 packages Mill Hill size 6 beads.

28 sts/38 rows = 4"/10cm in stockinette stitch.

This may be one of the most versatile hat patterns ever. Bead it, or not. Knit it in a colorful hand-dyed yarn, or choose a sedate solid. Add in a few extra rows of knitting after the increase rounds, but before the decrease rounds, for a bit more slouch. Take two different yarns and knit them as one. Are we missing anything?

Why yes, STRIPES! Try alternating one-row stripes. After knitting the band in your main color, begin the increase rounds with a contrasting color (leaving your main color yarn attached). After completing one round, knit the next round in your main color by taking it under the contrasting color. Continue in pattern, alternating main and contrasting colors, always taking the new color from below the just knitted color. You don't want your two colors to twist.