this is mine, I used 1" sashing that finished at 1/2". By doing that, I was able to cut large sqaures and cut them apart and with the sashing and sewed back together, I was back at the original size. no need to figure the math so they would all fit back together correctly like using a different width of sashing. You do have to pay attention to which sides of each piece you need to put sashing on.
