As far as judging the seam, you can buy a little circle with a small hole in center that you put the pencil lead in and roll it around the outside edge of the template (must be stiff or thicker than paper to work). The pencil will mark a 1/4" edge around the template. Don't know the name of it and can't look for it right now. DH is asking where his dinner is. It's only 5pm!! They are so impatient!