From the Knit Rowan website:
Knit this womans sleeveless waistcoat from Rowan Knitting & Crochet Magazine 57, a design by Lisa Richardson Original denim using Cotton Glace (100% cotton) knitted in reverse stocking stitch with two front pockets. This knitting pattern has a two star difficulty rating.

Finished chest width dimensions AFTER WASHING:
43: 48: 54: 60: 67 cm
17: 19: 21½: 23½: 26½ inches

Yarn information:
Photographed in Memphis 001
7, 8, 10, 11, 12 skeins
700, 800, 1000, 1100, 1200 yards

Also published as Wild West in Simply Knitting 136

Extras:
QTY (8) RW5021 buttons from Bedecked

Gauge notes:

• Denim will shrink in length when washed for the first time. Allowances have been made in the pattern for shrinkage (see size diagram for after washing measurements).
• Before washing using larger needles: measured over reverse stockinette stitch, 20 stitches and 28 rows = 10 cm.
• After washing using larger needles: measured over reverse stockinette stitch, 20 stitches and 32 rows = 10 cm.