The hem material is 3" wide. I fold it in half (following the outline of the sail,) then fold it again, resulting in a hem 1.5" wide (wide enough to fit a grommet.) The corners of the sail can be done many different ways. Some people cut off the excess material, others fold it and stitch it in. Some people even stitch in patches of Dacron to give the corners extra strength. I don't sew reinforcement rope inside the hem - you just don't seem to need it. If you do choose to use reinforcement rope inside the hem, don't use it on the leech - your sail will 'cup' and that's a bad thing.