How to Sew this Beginner-Friendly Mosaic Quilt Block using only Half Square Triangles and Squares
The Mosaic quilt block is an easy, beginner-friendly design made entirely from half-square triangles and squares, coming together in a unique pinwheel pattern. Traditionally pieced in two colors, this 12" quilt block also looks fantastic scrappy or with multiple fabrics. Follow this simple step-by-step tutorial to piece your own Mosaic block in no time.
Fabric Requirements for a 12" Finished Mosaic Quilt Block:
- Light/White: 14 - 3" squares, and 4 - 2.5" squares
- Medium/Blue: 4 - 3" squares
- Dark/Burgundy: 6 - 3" squares
- Dark/Navy: 4 - 3" squares, and 4 - 2.5" squares
Or you can do like I did and use leftover half square triangles from your stash! Mine are all bonus HSTs from making Flying Geese units in other Mosaic blocks which you can find at https://fabric406.com/blogs/fabric406-blog/tagged/mosaic-blocks
Sewing Directions:
Half Square Triangle Units:
Step 1:
- Using the Light/White 3" squares and the colored 3" squares, make 28 Half Square Triangle (HST) units.
- Trim/square up the units to 2.5" square.
- You can find my tutorial for making HST units at https://fabric406.com/blogs/fabric406-blog/how-to-sew-a-basic-half-square-triangle-block
- Lay out the 28 Half Square Triangle units, the Light/White 2.5" squares, and the Dark/Navy 2.5" squares as shown in the picture below.
Putting It All Together:
Step 2:
Sew the units into six rows as shown below.
If you find working with six rows to be cumbersome, you can split it up into four Nine Patch units and then sew the Nine Patch units together.
Step 3:
Press the seam allowances in opposite directions from row to row. For example, I've pressed rows 1, 3, and 5 toward the right, and rows 2, 4, and 6 to the left.
Step 4:
Sew the rows together.
Step 5:
Press the seam allowances. As you can see in the picture below, I've pressed all the seam allowances in one direction but you can press however you wish.
Layout Ideas:
Here is the basic 4 x 4 layout using colors similar to the tutorial.
And here is the same layout as above but with narrow (1") sashing and cornerstones added.
Traditionally the block is made with just a light and a dark fabric like what is shown below.
How about a scrappy version! Using the same color for the larger triangle shapes gives a sense of continuity to the quilt.
Using two darks and a light fabric makes for another interesting layout.
This is an alternating layout where every other block is a large Hourglass block. Additionally, I added a 6" wide pieced border (Flying Geese and rectangles) to finish the diamond shapes around the blocks.
For a completely different look, here is an on-point layout where the block extends into the setting triangles.
Conclusion:
I really had fun using up some of my "bonus" Half Square Triangles to make this block. I also enjoyed playing around with all the different layout and color options for this Mosaic block! I especially like the scrappy version. You should give this easy block a try!
I hope you have enjoyed this tutorial. If you like it and want to see more, just click HERE to sign up for my newsletter and receive a free PDF quilt pattern called "Chained Weathervane".
Happy Quilting!
Elaine
P.S. Are you looking for more beginner-friendly quilt blocks? Check these out at https://fabric406.com/blogs/fabric406-blog/tagged/tutorials_beginning-blocks
P.P.S. Check out my Etsy shop at https://www.etsy.com/shop/fabric406