That is exactly what I thought was a good measurement : follow the wedge size. ...BUT ... the widest part of the wedge is 6 inches so I thought the 2nd border should be 6 inches except that when I rehearsed the layout the 6 inch border seemed a little too big! Immediately I thought someone here would have a better eye! 3 inch may be the solution... so much for exact 'formulas' ! Thanks