Plaid Texture Pattern (multiple of 13 stitches plus 4):
Row 1 and all following odd-numbered rows (RS): Knit.
Rows 2, 4, 6, 8 (WS): *Knit 4, purl 9; repeat from * to final 4 stitches, knit 4.
Row 10 (WS): Knit.
Row 12 (WS): *Knit 4, purl 9; repeat from * to final 4 stitches, knit 4.
Row 14 (WS): Knit.
Row 16 (WS): *Knit 4, purl 9; repeat from * to final 4 stitches, knit 4.
Row 18 (WS): Knit.
Row 20 (WS): *Knit 4, purl 9; repeat from * to final 4 stitches, knit 4.
Row 22 (WS): Knit.
When working the Back and the Sleeves, it looks best if you centre the pattern stitch. Place markers around the central 17 stitches of the row, then count out 13 stitches from those markers towards the edges, placing markers as you wish, to set the placement of the repeats. You don't need to have an exact multiple to make this pattern work, it looks tidy no matter what. Just work any edge stitches in pattern.
When working the Fronts, align the pattern stitch so that the 9-stitch stockinette stitch block sits at the neck edge. For the Left Front, begin WS rows 2, 4, 6, 8, 12, 16 and 20 with P9. For the Right Front, WS rows 2, 4, 6, 8, 12, 16 and 20 should end with P9. Count back to determine where to start the pattern. Note that this means that the patterning may not align at the shoulders - this is fine, it's not visible in the end result.
If you're working the Mostly Seamless option, treat the patterning in three body sections separately, so that the center Front edges are properly set up and the patterning is centered in the Back. This means that there might be a pattern transition between the sides and the back. If you wish, you can adjust the stitch counts on the lower body so that the patterns align.
About Plaid Texture Pattern: A textured pattern reminiscent of plaid and tartan fabrics.