The Beginner-Friendly Mosaic #18 Quilt Block Tutorial

• Light/White: 8 - 3.5" squares
• Medium/Purple: 8 - 3.5" squares
• Dark/Burgundy: 4 - 3.5" x 6.5" rectangles
• Dark/Blue: 4 - 3.5" x 6.5" rectangles

The Diagonal Stripe units are made in the same manner as a Flying Geese unit except that opposite corners are used instead of adjacent corners.

Using the four Burgundy 3.5" x 6.5" rectangles, four White 3.5" squares and four Purple 3.5" squares sew together four Diagonal Stripe units. In the picture below you can see the first four steps using the Purple 3.5" squares.

Note the orientation of the diagonal line. This is important!

• Mark a diagonal line from corner to corner on the back of the Purple 3.5" squares.
• Sew a Purple 3.5" square to the Dark Burgundy rectangle along the marked line (top image). Note the orientation of the marked line. Because this is a larger size unit, I also sewed another seam about 1/2" away from the marked line so I can get a bonus half square triangle!
• Match the corners of the Purple square and press (second image).
• Open the small square up and trim in between the stitching lines (third image).
• Refold (bottom image). You can also see the little bonus half square triangle that I can use in some other project.

 

Now you can sew the White 3.5" squares to the opposite corner of the Burgundy rectangle. 

 

Once again, note the orientation of the marked line.

 

Repeat Steps 1 and 2 for a total of four Diagonal Stripe units like the ones shown in the picture below.

 

Repeat Steps 1 and 2 only substituting the Dark/Blue 3.5" x 6.5" rectangle for the Burgundy one for a total of four Diagonal Stripe units like the ones shown in the picture below.

 

 

Lay out a Step 3 and a Step 4 Diagonal Stripe unit as shown in the picture below.

 

 

Sew the two units together and press the seam allowance toward the Burgundy unit as shown.

 

 

 

Lay out the four Corner units as shown in the picture below.

 

 

Sew the units into two rows.

 

Press the seam allowances toward the Dark Blue Diagonal Strip unit as shown in the picture below.

 

 

 Sew the two rows together to complete the block.

 

Press the seam allowance. You can see in the picture below that I've used the tweak/twirl/furl method for pressing, but you can press however you prefer.

 

Here's your basic 4 x 4 layout using fabrics similar to the tutorial.

 

In this example I switched the purple and dark blue colors. Looks so different!

 

In this version, a lighter blue was substituted for the purple. This makes for a patriotic red, white and blue quilt (for my U.S. viewers). Imagine it in your own country's colors. You could also use school colors, holiday colors, etc. for a lovely quilt.

 

I added in sashing and cornerstones to the basic 4 x 4 layout for this example.

 

For this alternating example I used a chain block and made the blocks only two colors plus white background.

 

Here I used a different chain block with lighter colors for the alternating block. This makes the Mosaic #18 block stand out.

 

For this on-point layout I made the background a medium olive-y green and used an alternating chain block that extends to the setting triangles.

 

And finally this monochromatic on-point layout features dark sashing and cornerstones and light tan setting triangles.

 

This Mosaic #18 block was quick and easy to sew together. I love that another star appears when multiple blocks are sewn together. And I had too much fun playing around with layout ideas! So versatile.

 

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. Did you miss the previous Mosaic block tutorials? Check out #21 at https://fabric406.com/blogs/fabric406-blog/how-to-sew-the-mosaic-21-quilt-block-a-traditional-block-with-a-modern-look 

and #13 at https://fabric406.com/blogs/fabric406-blog/the-mosaic-13-quilt-block-free-tutorial

and #2 at https://fabric406.com/blogs/fabric406-blog/how-to-piece-the-mosaic-2-quilt-block-tutorial

P.P.S. Check out my Etsy shop at https://www.etsy.com/shop/fabric406