Cut a strip of bias fabric about 1 wide fold in half lengthwise, right sides together, and stitch about 1/8 from the folded edge down the length of the strip. Trim seam allowances to 1/8. Attach a strong thread to one end of tube at the seam. Turn the tube inside out by drawing the thread right through the tubing with a heavy needle. Cut the tube into lengths equal to the finished length of the loop plus seam allowance. Place these pieces on the right side of the over lap, shaped as loops turned away from the edge of the opening. Tack the facing right side down over loop and machine along seam line. Turn facing to wrong side and tack in position. Loops will be now extending from placket edge. Button, matching to the fabric loops are fixed on the under lap.

Sew button using the double thread bringing the needle up and down through the holes. After working enough stitches bring the thread to the wrong side of the fabric and insert it into the previous thread forming a small knot. Buttons with 4 holes may be sewn in the shape of a cross, two parallel lines, a square or an arrow head.