I'll start with....I haven't printed any!
Just looking at patches that have already had the edges stitched and thought "Wouldn't there be a white line between the stitching and the main print?"
So assume the patch is white, press it all black, wouldn't there be a white line inside the stitching due to the ridge? I can see the stitching would take the dye, the main body would take the dye, but where it sits a bit proud at the junction of stitching and fabric surely there would be a line.
Just wondering over a cup of coffee ... back to work now.
Janners.