This bobble cardigan is made using a simple dc stitch for three rows then a bobble row. It’s easy to work up. Then the arm cuffs and edging is made with a sc rib stitch.

Materials
dk / weight 3 yarn (see size chart)
3.5 and 4 mm crochet hooks
6-8 x 20-30 mm buttons

Written in English US terms with abbreviations for UK

Gauge
With a 4mm hook
18 dc x 8 rows = 4”

It is possible to make this cardigan in aran weight 4 yarn with a 5mm crochet hook with a gauge of 14 dc x 7 rows = 4” this would make the chest measurements as follows: XS = 41”, S = 46” M = 51” L = 56” XL = 61” 2XL = 66” Please note the yarnage may alter as I have not tried this myself The ribbing would need a 4.5mm hook.

The PDF is 26 pages including photos and short youtube for buttonband.