You do not have to apologize for not understanding/using 'the terminology'. We have all been there, done that. ;)

The most challenging for all of us (beside terminology) is to have accurate/constant 1/4 inch seams. Plus our cutting needs to be accurate. Then we have to perfect our pressing, NOT ironing! Once these have been mastered, then our blocks should (hopefully) come out to be all the same size the pattern suggest.

BUT remember we are all not perfect. We also have learned to perfect the usage of seam rippers. :)

this is one of those perfect examples of how an error can add up-
with that many pieces across it is easy to wind up off---
if you are only 1/8" off on a seam you may think---that's not a big deal- i will leave it---but in 8 seams you are a whole inch off!
one of the reasons it is helpful to trim/square up & check for accuracy as you go-
it could be all of your pieces are correct- but your seams somewhere along the way started getting a little larger- or smaller---so, you should look at the back & see where you started having the problem & go back that far- hopefully it's not too far back...good luck-
people often will think---only 1/8" or even 1/16" of an inch is nothing to worry about---but if there are many pieces---those variations to add up---quickly

I mark all my seams for the 1/4 inch seam rule

I usually check my blocks before I sew them into rows and yes, I do square them up if they don't match. Then I press each row so the seams nest when the rows are assembled. That way it becomes clear immediately if something is off. IF it is off, I gauge if the problem will be noticeable when the quilt is done OR if it bothers me. Then I take out (cursing of course) my booboo and fix it. I may lose some time, but the result will make me much happier.

Before you do anything measure the squares and blocks to see where the error started and how it continued. It might be only one block and it would be easy to fix that. Pleats or gathers are not desirable embellishments in quilts unless they are part of the design.

2.5 inch nine patch block is tiny, tiny, tiny. what ever size they are, they need to ALL be the same size before being sewn together. you will have to rip out stitches and fix the problem. seriously.

So I got home last nite, and took off the 3 rows that I suspect have the issue - the balance of the quilt is flat with no fullness or ruffles on the edges. I'm measuring each block in each row and have taken apart some of the seams, where I was 1/8" off on one side or the other, I hope to finish my de-assembly process tonite and by Saturday mid day, I should have everything put back together. Thank you all for your comments. I'll post pictures of the 'finished' product probably in a week :-) I'm excited to see if flat, quilted and bound! Thanks again!!!

Good choice, Wtx. If you're like me, your eyes would have always gone to that dart/pleat area. I hate ripping but always find I'm glad I did. (or I throw the item in the closet in The Box That Will Never Be Opened). Can't wait to see your pics.

Glad you decided to correct the problems -

Jan Rocks!