I took a class on sewing narrow borders, some 1/4" wide. We sewed them backwards from the usual way. Instead of having the seam on the right of the needle we sewed the seam on the left. I haven't made narrow borders in a long time so I'd have to make a few practice ones for it all to come back to me. I do remember the borders being very straight. I sewed 1/8" up to 3/4" borders on my practice piece.