This came out pretty interesting,
although I went a bit overboard in mixing stitches by the time I finished the brim.
The tunisian stitch I used here was Gobelin (aka Full). This is quite a beautiful stitch, I think.
The knit part is so much shallower that it’s essentially a vent.
You can see that the knit (stockinette) part stretched out a little while I was wearing it. It was (if anything) tighter than the rest originally.
I did this in (cheap) short-staple cotton yarn,
so it’s a very comfy hat band for summer. 🙂