Diamond Back Quilt Block Tutorial with Bob
I’m calling this one Diamondback, and what makes this block so much fun is the way it comes together. The cutting and assembly are a little different from the traditional quilt blocks I usually make, but once you see the process, it all starts to make sense. I used Crosshatch Midnight by Benartex with a solid background, and when several finished blocks are rotated together, they create a beautiful geometric diamond design. There’s also very little fabric waste, and one fat quarter can provide enough print fabric for four blocks. Let’s get started!
Step-by-Step Instructions
Step 1: Cut Your Starting Rectangles
Cut:
- One 9" x 10½" rectangle from your print fabric
- One 9" x 10½" rectangle from your background fabric
For my print, I used Crosshatch Midnight by Benartex.
A fat quarter can be divided into four of these 9" x 10½" sections, giving you enough print fabric for four Diamondback blocks.
Step 2: Cut the Rectangles Into Sections
From each 9" x 10½" rectangle, begin by cutting a 3" strip.
Cut the remaining fabric into 2½" strips.
From the 3" strip, cut:
- Three 3" squares
Your remaining pieces will include strips or sections measuring:
- 2½"
- 4½"
- 6½"
- 8½"
There will be a small amount of leftover fabric that will not be used.
Step 3: Make the Half-Square Triangles
Pair each 3" print square with a 3" background square, right sides together.
Draw a diagonal line from corner to corner.
Sew a ¼" seam on both sides of the drawn line.
Cut directly along the drawn line and press your half-square triangles.
You will make six half-square triangles, but you only need five for one Diamondback block. Set the extra HST aside.
Step 4: Lay Out the Half-Square Triangles
Arrange your five half-square triangles diagonally so they look like a set of steps.
Position each one so the print portion is in the bottom-right corner.
This stepped layout will create the foundation for the block.
Step 5: Add the First Small Section
Start with the first half-square triangle.
Use your smallest coordinating background piece to create a section that is the same size as the next portion of the block.
Sew these pieces together using a ¼" seam allowance.
Step 6: Continue Building the Block
Continue adding the remaining strips one at a time, working from the shortest piece to the longest piece.
The assembly is similar to building a log cabin block. Each time you sew on another section, the block grows outward.
Continue adding your:
- 2½" section
- 4½" section
- 6½" section
- 8½" section
The seam allowances will bring the pieces into alignment as the block grows.
Step 7: Check Your Block Orientation
Before sewing each new section, double-check the direction of your half-square triangles.
I even turned one of mine the wrong way while making the tutorial! Mistakes happen to every quilter, so take a second to check your layout before stitching.
Step 8: Arrange Your Diamondback Blocks
Once your Diamondback blocks are finished, rotate them in different directions and place them together.
This is where the design really comes to life. The half-square triangles and surrounding strips connect visually to create the larger Diamondback pattern.
I love how different this block is from a traditional assembly method, and I hope you’ll give it a try. Follow Sewing Parts Online on Facebook, subscribe to our YouTube channel for more quilt tutorials and, as always, Happy sewing!
