Big Batch HSTs

There are many ways to make half-square triangles (HSTs), and I've used most of them. How many you need for your particular project, and how scrappy your project is may determine what method you use. Two, four, and eight at a time seem to be popular quantities. {Click the numbers for tutorials for each.} Well, for my current project, I need over 100 of the same fabric pairing. So I wanted to make more at a time. 18 felt like a huge jump from eight, and it was really quite simple. Here's a tutorial that makes 18 - 2 1/2" HSTs (2" finished). I'll have a few notes at the end if you want to make a different size.

Cut 2 - 9" squares, one of each of your fabrics. Layer the 2 fabrics, right-sides together. Using a fabric marker, mark a grid on the back side of 1 of the fabrics, marking at 3" intervals both horizontally and vertically.

Now mark diagonal lines as shown.

Take your fabric to your machine and sew a scant 1/4" on either side of each diagonal line.
(I stitched with contrasting thread so you could see the stitching easily.

Being very careful not to move the fabrics as you cut, use your ruler and rotary cutter to cut along all vertical, horizontal, and diagonally marked lines. And here's what you'll have!

One thing to notice with this method is that you've sewn over the tips of most of the HSTs. But it is such a short little seam once you have cut the HSTs apart, that one quick flick of your seam ripper, and that little seam is gone.

Now press your HSTs as desired and trim to size. Note that the dimensions I use leave you very little excess to trim away.

You can see the bits I trimmed away in the next photo.

SO, if you aren't comfortable with cutting it that close, I'd suggest starting with 9 3/4" squares of fabric, dividing it into a 3 1/4" grid for 2 1/2" HSTs (2" finished).

IF you'd like to make a different size HST, the basic formula is:
size HST (2.5") X 3.6 = size of fabric squares (9")
Remember to round up if you like a little more leeway. And the size of your beginning fabric squares needs to be divisible by 3. Note that other sizes were not actually tested.

By cutting a 9" WOF of my 2 fabrics, and then cutting squares from there, I was able to get 4 sets - or 72 HSTs - in no time at all. And I don't see any reason you couldn't expand on this idea and make even more. Yay.