Size 6 (4mm) needles cast on 90 stitches using Tilly Buddy cast on.
Knit 6 rows stockinette for curled brim.
Start helix knitting ro avoid false seam.
Knit 9 ridges of garter stitch in purple then switched to larger size 10 ( 6.5mm) needle for body of hat and alternating black and purple rows beginning with a knit row to make sure the stripes look clean.

10 garter stitch ridges ( 5 purple and 5 black)
Then continue to top of the hat in black.

Place markers every 10 stitches and knit 2 together before each marker on every knit row until only 9 stitches remain.
Crown to brim is 8”
I don’t really like hats knit in Bulky yarn. Too heavy and stiff.
Perhaps I should have used larger needles but still, not a fan of bulky yarn.