TYSS: Diamond in a Square

Okay, back in the saddle!

The next block for the Test Your Skills Sampler is the Diamond in a Square block, sometimes called Square in a Square. For the sake of clarity, I’m calling it Diamond in a Square to differentiate it from the popular log cabin variation that’s also called Square in a Square.

If you’re following the White & Bright layout, this block contains an assortment of fabric, ending with the background as your final round. The block finishes at 9″ (9 1/2″ unfinished).

This block can be frustrating if you have trouble with accurate 1/4″ seams. The Skill Builder Series post about this component provides two different methods, one using triangles and the other using squares. Unfortunately, the one using squares only works for a single round with a plain center. Multiple rounds and pieced centers just don’t work.

Traditional Method

I’ll be honest, I took the cutting instructions for this block directly from EQ7, and I don’t understand the logic behind some of the instructions. Everything works properly, but I can’t explain why sometimes it has you cutting squares in half diagonally once, and sometimes you cut them in half diagonally both ways. I decided to just go with it, since calculating the sizes manually was overtaxing my brain.

Cut (2) 1 5/8″ background squares (or cut 1 3/4″ squares and trim later)
Cut (2) 1 5/8″ color squares (or cut 1 3/4″ squares and trim later)
Cut (1) 3 1/2″ color square, then cut in half diagonally BOTH ways
Cut (2) 3 1/8″ color squares, then cut in half diagonally ONE way
Cut (1) 5 3/4″ color square, then cit in half diagonally BOTH ways
Cut (2) 5 3/8″ background squares, then cut in half diagonally ONE way

Sew the 1 5/8″ (or 1 3/4″) squares into a four patch and trim to 2 3/4″.

Following the assembly instructions in Method 1 of the Skill Builder Series post, add each round of triangles. Be careful not to stretch the fabric, and sew accurate 1/4″ seams. Trim the points that stick out at each side before sewing the next round. (The points are often called “Bunny Ears” for obvious reasons!)

If you wish to cut the triangles larger, you may. Be sure to trim after EACH round is added, otherwise your block will be a mess!
After adding round 1 of the triangles, your block should measure 3 5/8″.
After adding round 2 of the triangles, your block should measure 5″.
After adding round 3 of the triangles, your block should measure 6 7/8″.
After adding round 4 of the triangles, your block should measure 9 1/2″.

Alternate Method

If you struggle getting the accuracy you want using the traditional method, you can also foundation piece the block. You will have to make the center four patch separately (not foundation pieced), and then pin or fuse it to the center of the foundation. Triangles are easily added from there. If you are familiar with foundation piecing, it’s simple to draw the block on your own. Draw a 9″ square (use newspaper or a cut up paper bag if you don’t have larger paper), and find the center of each side. Connect the center points, then find the center of each of THOSE lines. Connect those center points, and repeat two more times. Add 1/2″ seam allowance to the outside of the block.

For those of you who have not tried foundation piecing, wait just a bit. Both Jeanne and I will be posting instructions on foundation piecing before too long.

Be patient with the piecing, remember to sew scant 1/4″ seams, and you should be able to create this block. If all else fails, set it aside and we’ll work it out with foundation piecing later!

Let me know if you have any questions!



  1. I think EQ gave you cutting directions so that the long edge of the triangles is on the straight grain (1 square cut on both diagonals) when the long edge is vertical/horizontal in the block. And the long edge is on the bias (2 squares cut on 1 diagonal) when the short edges of the triangles are horizontal/vertical in the block.

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