Hanging head in shame.. Kensington you are absolutely correct. Those blocks make exact 12" blocks when finished correctly and hell with scant they would have to be made with 1/8th inch seams to make a perfect 12.5 which I think is not realisitic at all. Who sews with that kind of allowance so those who have done this before where did you find blocks that are 12.5 inches after you have sewn them? I cant find those patterns. My blocks are perfectly 12 inches just did two. Its great they are perfect in size BUT where is that .5 that I need? GRR just found a pattern I like too. It was fun to put together and is a nice block. One would think a person does not need to do mental math to change up the patterns so I think there must be another answer.