Lilyquilt: Half-Square Triangles Tutorial: Eight at a Time

A few months ago, I wrote a tutorial on making half-square triangles two at a time. That technique works great if you only need a dozen or so. However, I had plans to make a baby quilt entirely out of half-square triangles, and I wanted to make them more efficiently. I discovered a way to make eight at a time, which worked great for a project where I needed so many.

The quilt is all assembled, and I'm so excited, it looks awesome! I just basted it, and it's next in line for hand-quilting after my great-grandma's bow-tie blocks quilt. Now, I have to share how I made all these half-square triangles without losing my mind.

1. First, from both fabrics cut squares double the size you want your half-square triangles. (I'm using white and blue fabrics here.)

I wanted my squares to be 3" in the quilt, so I needed them to be 3.5" before assembling. I like to make my half-square triangles half an inch larger than I need them so that I can square them up first, so I made them 4" square. For 4" half-square triangles, I cut 8" squares from both of my fabrics.

2. Next, mark sewing and cutting lines. I usually mark the lighter fabric so it's easier to see.

On the wrong side, mark the middle of the square both horizontally and vertically. Then draw diagonal lines from corner to corner. Pin your two fabrics right sides together.

3. Sew 1/4" away on both sides of both diagonal lines. You should have 4 stitching lines.

(oops, I forgot to take a pic before cutting, but you can see my stitching here)

4. Cut on all four marked lines. You should now have 8 triangles with stitching on the long side.

5. Open up your triangles and press the seam toward the darker fabric.

6. Use a rotary cutter to trim all the squares to the correct size. This is easiest with a small square ruler that has a 45 degree angle marked.

Line up the 45 degree angle along the triangle edge. It's important to line up the angle so the points of your triangles match when piecing them together.

Trim a little from all four sides to square it up. Here, I'm trimming to 3.5". As you can see in the picture, you won't be trimming off very much and you might be tempted to skip this step. Don't skip it, or your patchwork will be all wonky and very frustrating.