Disappearing Nine patch size question
 

I am tasked for a project for our guild, to come up with a 6 inch finished ( 6 1/2" unfinished) disappearing nine patch block pattern. Just the basic one! But I cannot get the measurements to come out to the specified size...
Can any one point me in the right direction??? Please and thanks!

Shouldn't the size of the blocks be 2.5' that you would use for a 9-patch block?

Yes, that's correct. Three 2.5 inch blocks across, sewn together side by side, equals a width of 6.5 inches. Finished comes to 6 inches. Draw yourself a picture of a row of blocks, separated from each other by a space. Then in the spaces write down each seam allowance. The total will be 7.5 inches, which becomes 6.5 inches when everything is sewn together. This finishes at 6".

Here's a link to a disappearing nine patch chart. I would make a test
block first just to be sure.
http://raevenfea.com/quilting/disappearing-nine-patch/

Julienm1 & Synnove the measurements that you have would be for a regular nine patch, however Elaine is asking for a disappearing nine patch block to finish at 6 inches. If start with 2 1/2" blocks when it was cut in quarters and sewn back together, it would be at least 1/2" too small. Unfortunately, the math on the page http://raevenfea.com/quilting/disappearing-nine-patch/ doesn't have the size to finish at 6 inches, because it is said "some common block sizes, like 6″, 8″, and 12″, end up requiring the starting squares be cut to third-inches, so I didn’t include them above."

maybe this will help?
scroll down to "calculate the daughter size" and you will find a formula to get to a 6 1/2" block:

https://www.thesprucecrafts.com/disa...-quilt-2821751


here is another list of already calculated sizes including 6.5"
http://raevenfea.com/quilting/disappearing-nine-patch/

Oops! You're right. Well, if it were me I'd just tell my group, "Hey, guess what? We're going to make these blocks in an easier size!" But, that's just me.

This block will take away 2” in seam allowances. To make a finished block at 6” you will need to cut pieces at some odd measure. If you start with 2.75” pieces your finished block will be 6.25”

I usually start with paper units and glue until I find the right size for each cut. It may take a little time at first but it's always right.

Perhaps if you experiment with 3" pieces and use a larger seam allowances you should come close.