I have only one F & P ruler, an 8 x 14. I love the size and use it alot. But the lines are not dark enough for me! I do not buy specialty rulers anymore, because I know I will not make more than one of any quilt. And I do not take retreat classes that require them...cost of class often goes up $30 by adding the ruler! If it is just for a certain size or shape, the local hardware store may be able to cut inexpensively out of plexiglass.