Check out a tute I posted just yesterday; go to the last page of the PDF tute, second from the bottom.
http://www.quiltingboard.com/t-140936-1.htm
With the tute in hand, and this PM in front of you, read the following:
With this trick, measure the side of your border.
Divide that measurement by any number that can be divided again by 2 and that gives you a decent cutting size; e.g.
4 divided by 2 = 2
5 divided by 2 = 2.5
6 divided by 2 = 3
7 divided by 2 = 3.5
The first number (4, 5, 6, 7,) is the size of sawtooth blocks (in pairs).
The second number is the size you will cut EACH rectangle and that same number is the size of the SQUARE you will cut to snowball the rectangle.
This will make the shape shown on the tute page, of course.
If you want the 'teeth' to be sharper, just snowball the same side of EACH rectangle so the 'teeth' each angle in the same direction.
PM me if you have questions. Enjpoy!
Jan in VA