Twelve Triangles Quilt Block Tutorial: 2", 3", 4", 5", and 6" finished block

The Twelve Triangles quilt block is rather like a cousin once or twice removed to the Square in a Square or Economy quilt block. It simply has an additional round of HST to add to create the design.

Click either image to go to the tutorial for that block, or to download the paper piecing patterns for it.

Paper piecing is my technique of choice. The reasons are three-fold: 

• We avoid the fabric-gobbling Connector or folded corners techniques
• We don't need to purchase a specialty ruler (i.e., Corner Pop) to make it
• The accuracy is A-MA-ZING when you sew on the line

Time to get to the 'thing'!

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Download and print the paper piecing pattern

Stitch every seam in this same manner...starting and stopping a generous 1/4" from the end of the marked sewing line.

For our 6" sample, the #2 patches don't overlap, so I didn't stop to press the first #2 open.

For smaller blocks you WILL need to press before adding the second #2. If you've starched your quilt fabrics, you can give it a good fingerpress and save you a trip to the iron.

With RST, layer the second #2 with the opposite edge of #1.

Stitch.

Now press at the iron.

With RST, position #3 on an open side of #1, centering the patch.

Stitch.

Fingerpress it open or press at the iron, depending on the size of your Twelve Triangles block.

Add the second #3.

At this point, I like to take scissors and trim away those dog ears to remove the excess bulk. I've removed the first of four at the red arrow. 

Press at the ironing board.

It's time to trim to establish the SAs for the next round of triangles.

At your cutting mat, printed side up, align the edge of your ruler with the solid line between #2/#3 and #4 on one side. (red arrow)

Fold the pattern back on itself using the edge of the ruler. You will pull the fabric and stitches away from the paper pattern. The paper will rip a tiny bit. That's normal.

If it rips too much, use a piece of Magic Tape on the printed side. DON'T press on the tape. It'll gum up your iron.

Below I'm using the Add-A-Quarter Plus Ruler (12" version). There is a 1/4" lip that 'catches on the fold, making this trim job virtually foolproof...

...and this fool needs all the help she can get! ;)

Trim away the excess fabric sticking out. It's the bits of our Turquoise Grunge above.

Repeat for the three remaining sides.

We'll use this same trimming technique after we add the #4s and #5s.

Here is the 2" finished version of this block after trimming the sides. Perfect points and 1/4" SA. Ready to add the #4 and #5 triangles.

Back to our larger sample, with RST, align the long bias edge of a #4 with one #2/#3 side.

Since I'm adding a lighter patch on top of a darker one, I like to nudge the edge of the light #4 a couple of threads past the edge of the darker #2/#3. That way, the darker fabric won't shadow through the top of the quilt block.

Our patches are oversized, so you DO have a bit extra. And a few threads is all it takes.

Sew just like we've done all the seams to this point.

Add the second #4, nudging a couple of threads past the edge again to avoid any shadowing through.

Press.

Add the first #5.

And then the second one.

Trim away the dog ears created by adding these last two patches.

Press.

Trim away the excess fabric in the #4 and #5 patches just like you did for the #2s and #3s.

Repeat for all four #4/#5 patches.

Your block looks something like this after trimming.

All our points are intact and pointy. AND we've got the perfect placement line to position our last four patches accurately.

Match the edges of the first #6 with a trimmed #4/#5.

No need to nudge the patch a few threads because we're adding a darker patch to a lighter one. No chance of shadowing with this round of #6s and #7s.

Stitch from the printed side just as you've done for the first two groups of triangles.

Press.

Add the remaining #6 and press.

Finally, it's time to stitch the two #7s.

Finish with the second #7.

All the sewing is done.

Give your Twelve Triangles a good pressing.

Return your sewing machine to your everyday settings.

Re-install your favorite quarter inch presser foot. Adjust the needle position if needed. Increase to your normal piecing stitch length so your already for your next sewing excursion.

Move to the cutting mat, and trim the block to its unfinished size. That number—the bigger one—is in the SA allowance on the pattern itself. 

For our 6" finished sample block, we're trimming to 6½" x 6½"

Now with the ruler out of the way, these are the results of all that trimming.

Time to remove the paper. It's easiest to remove the paper pattern in the reverse order of how they were stitched. That means remove #7, then #6, etc.

From the front side, here is our finished Twelve Triangles quilt block. None of the points within the block are cut off. The outside points are all exactly 1/4" in from the cut edge. 

Gotta love paper piecing!

You did the thing!

High-five yourself for piecing the ultimate beginner triangle block—those perfect points prove you've got this!

Happy quilting!