I made a strip quilt with the blocks finishing out at 9", and did not use a foundation. I sewed the strips together, and ten placed my template on the strips diagonally, and cut. I have to admit after I got it started, I was nervous about not using a foundation, but I starched the heck out of the fabric before I cut, then starched the blocks. I took it to the LAQ to be quilted, and she did not have a problem with it, and the quilt is quite nice. But I think if I made another one with that size blocks, especially if I were going to slash the blocks and reposition them, I would use a foundation.