Free Alternate 3×3 Rib Knitting Stitch.
Multiple of 6 sts + 3
Row 1 (RS): *P3, sl 1 wyif, k1, sl 1 wyif; rep from * to last 3 sts, p3.
Row 2 (WS): *K3, p3; rep from * to last 3 sts, k3.
Row 3: *P3, k1, sl 1 wyif, k1; rep from * to last 3 sts, p3.
Row 4: *K3, p3; rep from * to last 3 sts, k3.
