Introduction
I’m offering this simple hat pattern for free with a kind request: I’m currently training for a half-Ironman to fundraise for the Sierra Club. Please stop by my fundraising page between now and the end of July and pitch in a little something if you’re interested and able. If you’re not able to donate at this time, consider giving me a signal boost. Many thanks!

As this is such a straightforward pattern, it makes a perfect template for customization. Pick your favorite stretchy cast on. Mine is a tubular cast on, but if that seems like too much fuss for a simple project, options abound (including the humble long-tail cast on; just keep it loose!) This hat has a 19 in/48 cm circumference as written. That will fit most adult heads with some amount of negative ease and a medium-ish kid’s head with no ease. If you prefer a roomier fit (or you want to size down for a baby), see the Notes section on how to modify your finished size.

Notes and modifications:
● For a stretchy edge, I like to use a tubular 2x2 cast on (commercial yarn samples), or a twisted German cast on (handspun sample).
● This hat is easy to size up or down by adding/subtracting cast on stitches by a multiple of 12. For example, for the given gauge: cast on 84 stitches (96-12=84) for a finished hat that measures 17 in/43 cm in circumference. The remaining stitch counts after each decrease round will change, but the decreases will align correctly.
● Another way to modify the hat’s size and feel is to change yarn weight and gauge. In the dark blue commercial yarn sample, a bulky yarn and size US6/4mm needles (ribbing) and US8/5mm needles (stockinette portion) were used for a gauge of 18 sts and 26 rnds = 4 in/10 cm. The resulting hat measures 21.5 in/55 cm in circumference.

Yarn:
● Aqua sample: Malabrigo Rios in Water Green (210 yd/192 m per 100g, 100% merino wool) -- about 110 yd/101 m
● Dark blue-purple bulky sample: Malabrigo Mecha in London Sky (130 yd/119 m per 100g, 100% merino wool) -- about 125 yd/114 m
● Handspun sample: 2-ply worsted weight (approximate) wool blend from Hobbledehoy fiber in the Lover’s Leap colorway -- about 150 yd/137 m

Additional materials:
● US size 4/3.5mm needles and US size 6/4mm needles (circulars and/or DPNs - your preference) or size needed to obtain gauge
● Darning needle
● Stitch marker