Reply To: altering a man’s long sleeve shirt

[the_professors_assistantKeymaster]

This might be a little tricky with ready-to-wear clothes because I imagine that the underarm seam is serged and that the seam allowance left is very small. If this is the case, they’re not giving you much fabric to let the seam out and really, the only other option, is opening the seam and adding another strip of fabric, but this might look odd.