Originally Posted by
aggie
Please indulge me with this question. I understand a scant 1/4 inch. But if it's different from a regular 1/4, it would stand to reason that the blocks would measure differently. If you sew 3 two inch strips together, the center strip should measure 1 1/2 inches. What would it measure with a scant 1/4 inch? I don't get it.
You have the right idea -- blocks do measure differently -- but you are thinking about it in the opposite way. Sewing a regular 1/4" seam allowance will result in blocks that are a different size. A scant 1/4" seam allowance is needed to achieve the correct finished size. The video posted above demonstrates the difference in finished blocks very well.