This bonnet can be knitted in 4ply or Double Knitting weight yarns.

Instructions are given for two sizes.

If using 4ply yarn, use 2.75mm and 3.25mm needles.
If using Double Knitting yarn, use 3.25mm and 4mm needles.

There are instructions for an optional crochet trim.

If using 4ply yarn, use a 2.5mm crochet hook.
If using Double Knitting yarn, use a 3.75mm crochet hook.