Here Porter performs both visible and almost invisible witchery on a standard polo shirt. There's waist shaping, but on the plain back the shaping is done a few stitches in from the side seams. On the front, though, she establishes two little purl columns and performs the shaping around them. The result is form-fitting and prettily innocent, too (she recommends 0 - 2" ease; not much). Back neck is lowered a bit and squared off; sleeves have a decent cap.
