Pity the poor purl bump! Other than when working a knit-purl fabric, designers often go to lengths to ensure it doesn’t appear on the right side of the fabric. We even use a special technique to keep it from appearing in ribbing where there are color changes. The purl bump was first elevated to a design feature—rather than a mistake—by the Bohus designers in the 1930s, although that made it more popular afterwards.

I decided to explore and thus “celebrate” the purl bump in this design. When a contrast color is worked in one round of reverse stockinette, it produces not one, but two, clean horizontal lines of color. When a single round of purl is placed in stockinette fabric, a single garter stitch rib is created, which consists of alternating smile and frown purl bumps. I used both of these features in the colorwork band in this vest. To create purl bumps in the contrast color in the ribbing at the neckline and arm holes, a single round of contrast color is worked K1P1, the same as the main color, but the next round of main color is worked in reverse, as P1K1, so each vertical rib of the ribbing shows exactly one contrast color purl bump. And then the remaining rounds of main color are worked in K1P1, the same as the first few rounds.