A small amount of CC can be used as an optional contrast trim.

Finished measurements:
Across the back, from the midpoint under the armhole to the midpoint under the armhole: 9 (10, 13, 14) in. (23 25.5, 33, 35.5 cm)

Errata:
Row 3 (RS): k2 (4, 6, 8), m1, ^p1, k1, p1, c4f, p1, k1, p1^ m1, k5 (10, 21, 31), m1, repeat from ^ to ^ BUT working c4b instead of c4f, m1, k2 (4, 6, 8).