So - while taking a short coffee break from generating garbage bags yesterday, it occurred to me that I could just try setting down the string bag pattern while it was fresh in my mind. Lo and behold, it was not that difficult to do, and here it is:
Materials: This bag takes a little less than 400 yds (I'd estimate 375-ish) of DK to light worsted weight cotton or cotton blend twine / string. (I actually used Aunt Lydia's Denim Quick-Crochet, which I found at Walmart for around $5 for 400 yds - it is 75% cotton, 25% acrylic, looked and felt just like the cotton blend twine at the hardware store, but a bit cheaper).
Needles: I used 3.5 mm (US 4) dpns for the base, with a gauge of 4.5 stitches and 7 rows to the inch in stockinette. I switched to a 4 mm (US 6), 24 inch circular for the sides. I wouldn't worry overly about gauge, as long as you're close.
Using the half-hitch technique (and no slip knot at the beginning) cast on 8 stitches and divide between three dpns, preparing to join in the round. The cast on will be counted as round 1, to make the mathematical sequence clear.
Rounds 2 & 3: knit - at this point, pull firmly on the tail to tighten up the cast on.
Round 4: *yo, k1; repeat from* - 16 stitches
Rounds 5-7: knit
Round 8: as round 4 - 32 stitches
Rounds 9-15: knit
Round 16: as round 4 - 64 stitches
Rounds 17-23: knit
Round 24: *yo, k2; repeat from * - 96 stitches
Rounds 25-31: knit
Round 32: as round 24 - 144 stitches
Knit 6 rounds.
Round 1: *k2 tog, yo, k2; repeat from *
Round 2: *p2, yo, p2tog; repeat from *
Repeat these two rounds 32 times, or until desired length is achieved.
Knit 3 rounds.
Round 1: *yo, p4tog; repeat from *
Round 2: *(k1, p1, k1) into yo of previous round, k1; repeat from *
Round 3: knit
Knit 2 rounds.
*Insert right needle knitwise between first 2 st and pull through a loop as for cable cast on, placing it on the left needle. BO 3 st, sl rem st on right needle to left needle; rep from *
Make a 3 stitch I-cord as follows: using 2 dpns, CO 3 st, *k3, do not turn. Slide sts to right, pull yarn to tighten. Rep from* until cord is long enough to thread through the eyelets of the fully opened bag, plus another couple of inches. (If you are petite, and plan to carry heavy items, you may want to make the cord shorter to ensure it doesn't drag on the ground when stretched. It's just right as is for my 5'10" frame.) Thread the cord through the eyelets before binding off, and graft or sew the ends together. Keeping in mind that this join will bear a considerable load, it would be prudent to reinforce it, and leave long tails embedded within the cord.
Weave in the ends.