I'm considering using a D9P block in a swap that needs to be the typical 12-1/2" unfinished square.

Having never done a D9P before, my question is...

Do I increase the size of the center squares to 5" to allow for the extra seam that will be created in the regular 4-1/2" square of the 9 patch?

Or do I increase the size of the block to be cut to 13" and make all the squares 4-7/8" ?

Or is there a better way to do this and come out with the right size sqaure?

I have done a couple of D9P's this spring/summer, I have always made the blocks the same size.Good luck with your project!

The nine patch before you cut it has to measure 13 inches...so when you cut it in half both ways and sew it together it will be 12.5 unfinished. So your individual blocks need to measure 13 divided by 3 plus 1=5.33 So I guess I would make them 5 3/8......I hope that is right. I am sure someone else will let you know....

Great question...I just signed onto the board to ask the same question. Thanks Charismah for the answer....How about a 9" finished block? TIA
:-)

I did these at 12.5 unf in a swap. I used the 5 inch squares and cut as usual, then I square the 4 blocks up to 6 1/2 inches. I squared them up by putting the small square in the lower left corner on my cutting block and cutting off the sides that have the large square. Don't cut off the side with the small square.

I was wanting to ask the same question. Thanks for asking for me. Great answers.