Originally Posted by ghostrider

I think what bearisgray meant to say is the center strip should measure 1½" (2" minus the two ¼" seams). Keep testing until it does.

It's the same idea as getting your gauge right when knitting. Lots of ways it can be 'off' and lots of ways you can make it right. Find the easiest one for you. And test it again before you start any new quilt to make sure everything fits as it should. Saves a whole lot of time, energy, and frustration.