The original Nazo Vest uses Dancing Colors, a DK weight yarn, along with a sport-weight companion yarn at a gauge of 3.5 stitches / 7 rows to the inch in Garter Stitch. That's a very relaxed gauge that lends a nice drape to the fabric. For the Jacket version though, I envisioned a more structured fabric so I kept the gauge and changed the yarn choice to Brown Sheep Company's Lamb's Pride Bulky. You can see the difference. It's good. I'm liking it.
If you'd like more details on the Nazo you can find those along with the pattern in my Ravelry shop