8 1/2" Nine Patch Block
 

Hi,

Can anyone tell me what size blocks I would need to make a finished 8 1/2" nine patch block. If possible I will try to use strips, but I can't figure out what the width of the strips need to be to get a finished 8 1/2" block after sewn together.

The closest I came up with was 3 inch strips, three sewn together would give me a finished 8" block, I am not sure that is correct.

I think 3-3' would give you a 71/2 "....3- 3 1/2" would give you 9"...3 - 3 1/4 would give you 8 1/4. Soooo ....maybe 3 3/8????


I might do the 3 1/2 and trim????

3 5/16 is what EQ7 says. Make a test one first to be sure.

Each strip would need to be 3.3333 inch. If I calculated correctly. 8.5 plus .25 time 2 for each block equals 10 inches.
10 divided by 3 equals 3.33333333333333333333333333

Just do 3.33333333 and sew a scant bigger seam

Trimming would make only the outside squares smaller

3 1/3 is correct, but are you sure you want the block to be 8.5" finished? You mentioned that you thought three 3" strips would give you 8" finished, but that's incorrect; each 3" strip would be 2.5" finished, so you would get a 7.5" finished block, 8" unfinished.

For any FINISHED block size, if you want a 9-patch you need to divide the FINISHED block size by 3, then add 1/2 to get the strip size. Conversely, for any strip size, subtract 1/2 and then multiply by 3 to get the FINISHED 9-patch block size. For instance, for an 9" FINISHED block you need to divide 9 by 3 (giving 3) and add 1/2 (giving 3 1/2).

8.5 is a very unusual size for a finished block. Nothing really goes into 8.5 very nicely. If you look at Marcia Hohn's Quilter's Cache site, you won't see any blocks that are 8.5".

Don't sew a bigger seam, because you really do want the strips to be exactly 3 1/3 inches, using 1/4" seams, to get a block that is 8.5" finished.

This was IMMENSLY helpful and timely for me! Thank you all, especially dunster! The reason I require the oddball 8.5" finished nine-patch block, is that I'm cutting multiple fat quarters into four 9" square blocks which will be alternated with nine-patch blocks to make a patchwork-looking picnic blanket. Thanks to you all...

Dunster - thank you so much. I am a little rusty in my 'quilter's math' and that last block I made, I had to draw it out to make sure that I had the correct block size for a donation block. I was thinking of making some 9 patches next and your directions were very timely :)

Sylvia