Any gauge of flat bed knitting machine may be used. Each uses worsted weight yarn but on smaller gauge machines, every other and every third needle are used. Bulkies use every needle. Knitting is made very loosely, then felted. Gauge after felting is about 4 stitches/6.7 rows per inch. Requires yarn that’s 100% wool without a treatment such as Superwash. Exact size will vary with degree of felting.