Some factors in getting a block to finish at "the intended size"
 

Or - why your block is not finishing at "the intended size"

There will be absolutely nothing in this post that has not been mentioned many times before - but there might be something that a "newbie" has not thought of yet.

1) Some unwashed fabrics shrink when they are steam pressed. This will alter the finished size.

2) If one is not using a die-cutter for cutting the pieces, there may be variances in the size of the piece from the "exact" size. The way I cut squares - for example - I know they are about +1/32 of an inch from the "true" size. That does make a difference in a block with many pieces.

3) The seam allowance - what really matters is what is "showing" between the seam allowances. Doing the three strip test to check before starting out is worth the time and effort.
Here is one reference for how to do that:
http://www.connectingthreads.com/tut...ance__D95.html

4) If one uses starch - don't press/iron a soggy wet piece like you are rolling out pie dough. It will stretch the fabric.

5) Flatten rumpled fabric before cutting it. Iron or press it - I think using steam is better than a dry iron, but that's my preference.

6) I've heard that thread thickness matters. I have a huge supply of Coats & Clark cotton covered dual duty thread that I want to use up. Lots of threads about preferred threads on this forum.

7) Make a test block to see if it is turning out the way you want it to. Then make the adjustments. (of course, knowing where and how to make the adjustments comes from experience!)

Good post - thank you!

good list, thanks for posting them

We only do 3 things in piecing - cut, sew, and press - and you've covered all 3.

Good summary of many helpful tips. I would add 1 more...quality of fabric. Learned the hard way that quality fabric behaves much better than cheap fabric.
My New favorite piecing thread is Presencia 60wt, my seams are finally flat! Yay!!

You forgot unsewing and resewing!

I think washing before cutting is very important - I've had enough grief with not-washed fabrics, that I just don't want to take the chance of using not-washed fabrics.

So much emphasis seems to be placed on that seam allowance - and while it matters - the size of the pieces matters as much or more.

I have been meaning to measure the size of a strip when/if I used the June Tailor thingy as compared to "my" size of a strip. Or the size of the strips/pieces when cut by a die-cutter. Or using pre-cuts.

Even 1/64 variance of an inch across eight pieces -

Example - on eight strips - if the seam allowance is consistently only 1/64 inch more or less - on the first seven seams - 14 edges x 1/64 - 14/64 - that is almost 1/2 inch.

Great post, Bear

good info, Bear. I'd add not squaring up the "units" that make up the block--especially when a block has lots of pieces.

I recently ran into a new one. I was using a 4.5" square and always coming out shy on my 12.5" blocks, about three weeks later I found another 4.5" square in my rulers by another company and discovered that it was larger. If all else fails you may want to check your rulers for accuracy. I would have never thought about this had I not seen it with my own eyes.