I use my 6 x 24, but wish it were 6 1/2 x 24. I use my 15" square because the first one is not wide enough. I use my 6 1/2 inch square for squaring up my HST. I've used the X-block ruler, found it very cool, but because I was not willing to sew all the tiny triangles into squares, I wasted a lot of fabric. Still, I love the look of the finished quilt from X-block
x-block quilt
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