Turn of the cloth, a quest for accurate blocks, and sewing in general...

Turn of the cloth, one of those sneaky things that can confound a sewist, to me, it is, the mysterious shrinkage.  I've looked the term "Turn of the Cloth" up, Threads magazine has an explanation for a very specific instance.  Play with me, while I try to explain, mostly through samples.  This principal applies to quilt blocks as well as sewing garments.  We'll start with the quilt blocks first.


I need a 3"  block, how do I get it?    Here is a 3" block, no seam allowance, just a 3" block, to keep it simple.

Now we have two pieces of fabric, cut to 3" x 1 3/4".  When I sew up the seam and press open, I should have a 3" block, just like the one above.

The fabric is marked with a 1/4" allowance, we are sewing straight down the center of that line. (disregard the green tape for now)

Once pressed open, it is not a 3" block, it's not a terrible block, it looks to be 1/32" off.  Imagine if you have 32 blocks that are 1/32" off, at the end the finished length will be 1" off.  You'll ask, where did it go?  Why doesn't my border fit?  If it's a garment, that's taken up your garment ease. That 1/32 of an inch is the length the fabric needed to make the fold bend.  The thicker or stiffer the fabric, the more adjustment will need to be made.

I think we can do better. I want the needle to drop about a thread's width from the original seam line towards the seam allowance.  This should produce a slightly larger block.  Hmmm celkalee, this is your scant 1/4".

And I want to mark that edge with big wide painter's tape that I have around the house.

Let's try this again, I'm thinking we have a winner. The new block is at the top.

Now with a new found confidence, should we try four pieces to finish at 3", using the same seam allowance? The blocks are cut to 1 3/4" x 1 3/4"

Ok, how did this happen?  (besides missing the center point a squoosh), it's slightly bigger.  This can be remedied.  It will need to be trimmed or trued.  

Now we have a block that finishes at 3".......

And this is what had to be trimmed to get there.