QuiltnNan

I have a chart that shows all the disappearing blocks with sizes for original block size, finished disappearing block size and size of strips to cut the pieces. I wish I could share it with you but it is copyright. it does not give a finished d9p block of 12.5. It jumps from 11.5 to 13. It must be that the cutting sizes must be really weird for a 12.5 finished. The 11.5 finished starts with 4.5" strips and the 13 starts with 5.0". So you can see that the 12.5 finished would start with patches just under 5.0". If you really need 12.5" finished, I'd do test blocks starting with 4 7/8 and work down from there. Good luck.