This bag is knitted plain. The cables are created by sewing narrow strips of stockinette on in any design you  wish. Contrasting color cables and  intricate cables are easy as pie using  this approach and the way they were made is undetectable  after felting. 
YARN, GAUGE, SIZE AND MACHINE:  Surprise! All machines use the same yarn, a light worsted weight 100% wool.  Recommendations are Patons Classic Wool, Lion Fisherman’s Wool, Jaggerspun 3/8 run 2  strands together. Standard machines knit on every 3rd needle, mid-gauge on every  other needle and bulky machines on every needle. All machines use largest stitch size.  Bonds use key-plate 4. Passaps can use the pattern with standard directions but must  knit the first row after the cast on manually to get the yarn into the hooks where it  needs to be to proceed. Stitch counts refer to needles in work, not needle span on the  machine.