I n the meantime and if no one answers let me give you these clues to determining the amount of focus fabric you wll need. You say you are dong the lap size which is the 42x50 size.
The pattern appears to be constructed of squares. The angled look is created thru the angles of the black/white strips and the angle the blocks are put together. I counted 20 blocks which will probably be 9" finished since the 18" blocks will make a larger quilt.
If there are 20 blocks - there will be 3 across and 5 down.
If 9" then the blocks appears to be constructed in units of 3" If so then the black/white is a 3" strip leaving 6" for the focus. Focus square will be 6.5"x6.5" If 6.5" is divided into 42" (width of fabric then you will get 6 per 6.5" cut of fabric
You need 20 blocks. So will require 4 6.5 strips or 26"minimum of the foxus fabric to cut the 20 6.5 squars.
6 strips at 6.5 = 26"
Last edited by Holice; 12-06-2012 at 08:40 AM.