The Oslo Hat is worked in two strands of yarn held together from the bottom up in stockinette stitch. The first part of the hat is worked on a 40 cm 16 inches circular needle, while the top of the hat is worked either on double-pointed needles or on a circular needle using the Magic Loop technique.
Begin by working a swatch to check that you have the correct gauge.

Sizes:
XS (S) M (L) the approx. equivalent to baby (junior/woman) woman (man)

Measurements:
Fits head circumference 47-50 (50-55) 55-59 (59-62) cm [18½-19¾ (19¾-21¾) 21¾-23¼ (23¼-24½) inches]

Gauge:
22-23 sts x 32 rows = 10 x 10 cm [4 x 4 inches] in stockinette stitch on 3.5 mm [US4] needles

Needles:
Circular needles: 3.5 mm [US4] / 40 cm [16 inches]
Double-pointed needles: 3.5 mm [US4]

Materials:
100 (150) 150 (150) g Arwetta Classic by Filcolana (50 g = 210 m [230 yds]) or Sunday by Sandnes Garn (50 g = 235 m [257 yds]). Note that two strands of yarn are held together throughout, and that the yardage given is the total yardage needed.

Difficulty: ★ ★ (2 out of 5)

See the classification of difficulty here.

The blue Oslo Hat is knitted in Double Sunday by Sandnes Garn in the color Sailor in the dark [5581].

The dark brown Oslo Hat is knitted in Arwetta by Filcolana in the color Red squirrel [352].

The light brown Oslo Hat is knitted in Sunday by Sandnes Garn in the color Croissant [2345].