Couching is simply sewing a heavy thread in place with a finer thread. Its a retro technique, too, that was originally done by hand, but it works beautifully by machine as well. I use a zigzag stitch to secure the heavy thread in place.
How to Remove Scratches From Plastic Lens Glasses. There is nothing worse than putting on your glasses and realizing that you still can't see clearly because the lenses are covered in scratches. If you have glasses with plastic lenses you.