HeartStrings blocks are pieced on a 10 inch foundation block and are squared to 9.5 inches after the foundation is covered with strings.
I square my blocks from the back.
I will be trimming from all 4 sides of the block so for my first cut, I’m going to cut about 1/4 inch off the foundation from the top and the right side. Notice that the diagonal line on my ruler is running down my center strip.
Before I cut, I double check that my foundation extends beyond the 9.5 marks on the bottom and the left side of the block.
I trim up the right side and across the top.
I flip my block around.
And using the ruler to measure exactly 9.5 inches, I trim the remaining two sides.
Here’s my 9.5 inch block.
MaryQuilts.com 
Thanks for making this pattern available. I really like the completed quilt that you have pictured.
LikeLike
Your directions are so simple.I have made four so far from scrap material. Thank you for the pattern.
LikeLike
Thanks I just looked up the directions with the help of Sue Franks in MN
I have some old sheets I plan on cutting up and sending to her for foundations for the back of your blocks…. I just hate throwing away clothes or sheets if I can find a use for them..
LikeLike
I read e-mail with dates in 2010… is this project still valid
today??….. January 2012.
LikeLike
I hae several relatives who want to make string blocks for Quilts of Valor. They do not have anyone to make the quilt. Where can they send the blocks? Our group is making a whole quilt. Where do we send blocks to? Where do we send tops? Where do we send completed quilts. I could not find any addresses on your site except for a place to send backing fabric donations. Thanks, Our beginner quilt group has really enjoyed learning to make a whole quilt by this method. Thanks for your wonderful patterns! Karen Hansen momhansen@yahoo.com
LikeLike