Wednesday, January 17, 2018

Beginners Unite - Square In A Square

I'm adding a little how to for the Square in a Square Unit.

I started thinking that a tutorial for trimming the Square in a Square (SIS from now on) unit might be helpful, since our January block for the 2018 Monthly Color Challenge has one front and center.

Tips for stitching a Square in a Square Unit

You will need one square and four triangles. I am making a 4" finished SIS for this tutorial. My square is 3 3/8" and the triangles are two squares 3 3/8" cut once on the diagonal.  I like Quiltville's chart for sizes.

The triangles are over sized, meaning in this case we don't have to align centers, we can just eyeball it.

Sew a triangle to opposite sides on the square. Use a scant 1/4" seam allowance. Finding the correct seam allowance is important, I have a post about it HERE.

Press towards triangles.

Repeat with the last two triangles.

Press towards triangles. Give it one final *good* press to make sure you're working with a flat piece for trimming.


If you don't have a specialty ruler for trimming SIS, you can still use a regular ruler. This is how I have trimmed my SIS units in the past. Now, I love the Square2 ruler from Deb Tucker's Studio 180 Design.

Find the 1/4" seam allowance, from the top point and right point, and line up your ruler.

You will have a good amount to trim.

Rotate, line up the 1/4" seam allowance as well as lining up your 45 degree angle on the bottom left corner.  Your left and bottom edges should align with the needed measurement. In this case, the 4 1/2" lines.

Perfectly square, with 1/4" seam allowance from each point.

Happy Stitching!

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  1. Thanks for this tutorial, Jen! I sewed these just recently and probably did not square them up correctly. As a result, I had to keep matching and matching to get my points to line up.

    1. Danette, I hope this will be helpful to you in the future. It can be frustrating to match and re-match when you want to be sewing.


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