? about DP9 block...
 

To come out a finished 12.5" block, what would size of the 9 blocks be? Found charts of final size but none for 12.5".....

[I] found this but it comes out 12" finish

http://www.quiltingassistant.com/doubleninepatch.html

Are you sure you want a finished 12.5" block? That's an odd size.

If I remember correctly, your finished d9p comes out 1/2" smaller than the original finished 9-patch. That would mean making a finished 9-patch that measured 13", so each patch would be 13/3 finished, which is 4.3333" finished, or 4.83333 unfinished. That's a difficult size to measure! You might be better off making a larger block and cutting it down after you've sewn the d9p, if you really want 12.5" finished.

If you got this measurement from someone doing a swap or a group quilt, I would bet that they meant 12.5" unfinished, even if that's not what they said.

Nine 4.5" squares will make a 12.5" block... 12" when sewed into your quilt.

edit: Oops, I meant for a 9 patch block. If you are going to cut them again to make a DNP block, you need to start with 5" squares.

If you want a finished size of 12 inches - and assuming 1/4 inch seams -

Cut the four corner pieces 4-1/2 x 4-1/2
Cut the four side pieces 4-1/2 x 5
Cut the center piece 5 x 5

After the block is seen, cut, and re-assembled - it should measure 12-1/2 x 12-1/2 unfinished - 12 x 12 finished.

Actually, the ratios can be changed to alter the look of the block.

Love scrappy D9P!

If you are looking for the block to be 12.5", that means your finished block would be 12" (remember when you put the blocks together you are using up another 1/2"). So the instructions for 12" blocks are what you should use to have the individual blocks be 12.5".

12.5" is an odd size. Is this what the pattern calls for, or does it say 12.5" Unfinished? Sounds more like the unfinished and then finishes at 12" in the quilt. If I make something and it ends up an odd size, I just duplicate whatever I did to make all the blocks the same, because I want to avoid complicated fractions at all costs.

This is a cute block, but it is not a Disappearing 9-Patch.

I just finished a Disappearing 9-Patch using all 5 inch squares. It is 13 inches finished.
Four inches would be too small, but starting with 4 1/2 inch squares would make 12 inch finished 9-Patch before you cut it up to disappear it. Cutting it takes up another half inch, so you would end up with 11 1/2 finished.
4 3/4 in to start would come out to 12.5 finished.