Buttonhole stitch (worked by hand)
Working from the wrong side, insert needle in the edge, make a small loop, then run the needle through the loop from below and tauten the thread to make a kind of knot, which must lie exactly on the cut edge. Make the stitches close together for a firm cover. When you’ve finished the first side of the buttonhole, sew a corded bar over the end of the slit i.e. make several long stitches over the end of the slit and then cord these stitches (densely wrap thread this around this bar, also catching in the fabric each time). Then embroider the second half of the buttonhole and make a bar at the other end, darning in the thread underneath afterwards.