Half-Square Triangles – Fast, Easy and Accurate! Free Tutorial

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This week’s clue for the Orca Bay Mystery Quilt is to make 350 half-square triangle (HSQ) units that measure 2″ square unfinished, 1.5″ finished (when sewn into a block or the quilt itself). After all the cutting I did for the quarter-square triangle units I wasn’t looking forward to this step.

I did some digging around to see other methods people use and I found a really fast and accurate method.  I couldn’t believe how easy this was to do. Some notes to those doing Orca Bay – if you want lots of individual blocks without repeating fabrics, this method probably isn’t the one to use since each sheet of paper makes 18 half-square triangle units. I don’t have a lot of black and white fabrics that I’m working with so it works for me.

Firstly – download and print the PDF for the desired finished half-square triangle unit size. Remember that finished means once the unit is sewn to something else it will measure that size in your quilt so your unfinished unit will have 1/4″ seam allowance added

I.E.: 1.5″ finished half-square triangle unit is going to measure 2″ when you are done with this method before the unit is used in conjunction with another piece of fabric.  You will notice I’m using the 1.5″ template and my HST unit measures 2″ square – that is exactly what you want! You’re going to lose 1/4″ seam from your unit once it is sewn to something else so it’ll end up being 1.5″ in your quilt.  Use the template for the finished size HST unit that you want to end up with.

Measure the test square to make sure it printed out exactly 1″ square.  If it did you are ready to print it out on the paper you are going to sew through.  I used Carol Doke’s Foundation piecing paper which tears really well and sews nicely.  I’ve heard construction paper from the dollar store works well too.  You are welcome to use the paper of your preference.

Press your fabric well.  I recommend using spray sizing or starch to make sure it is really stiff.  Layer your two fabrics right-sides together.  Press.

I lay my paper on top and trim the fabric so I can make sure both layers are the correct size and then I press again.
Half-Square Triangle Foundation Piecing Tutorial
On your sewing machine set the stitch length to 1.0 or equivalent so that the paper tears easily when you are finished.
Half-Square Triangle Foundation Piecing Tutorial
Sew along the dotted lines on the paper and rotate when you come to an intersection. The needle/up down function comes in very handy here!
Half-Square Triangle Foundation Piecing Tutorial
Half-Square Triangle Foundation Piecing Tutorial
When finished sewing press again and take your sewn layers to your cutting table.
Half-Square Triangle Foundation Piecing Tutorial
Cut along the solid lines.  I like doing my vertical lines first!
Half-Square Triangle Foundation Piecing Tutorial
Rotate and cut your horizontal lines.
Half-Square Triangle Foundation Piecing Tutorial
Half-Square Triangle Foundation Piecing Tutorial
You will end up with a small unit that can now be cut in half!
Half-Square Triangle Foundation Piecing Tutorial
Remove the paper and take your little unit to your ironing station.
Half-Square Triangle Foundation Piecing Tutorial
Press your seam.  This test one I pressed open out of habit.  For the Orca Bay Step 3 Bonnie recommends ironing to the darker fabric.
Half-Square Triangle Foundation Piecing Tutorial
Measure and make sure your unit is the correct size.
Half-Square Triangle Foundation Piecing Tutorial
Trim the dog ears
Half-Square Triangle Foundation Piecing Tutorial
Each 1.5″ paper template will make 18 units so it doesn’t take very long to get 350.  I do believe I found my new favorite way to make HST units!


  1. Anonymous says:

    Thanks for the tutorial. As a newbie to quilting this is good to know. As I am currently planning some totes for all the girls the HST's will be so quick to do.
    Love the ease of understanding in your tute. Thanks again Katie.

    Sharon G
    South Australia

  2. I often use triangle papers THANGLES and Edyta Sitar 2 inch finished papers. (that is the size I need for my project)

    I like Edyta's papers since it is based on FAT QUARTER CUTTING system. I do not think they have other size triangle papers YET!

    THANGLES is an older product and the paper is TOUGHER, harder to pull out. But I am using what I have as I won a huge basket at a silent auction.

    Looking forward to seeing your finished project.


  3. Wow! thanks. Great tutorial. Makes me want to start a HST project. But I will certainly put it on the list. Had been avoiding it due to all the work.

  4. I'm not doing the Orca Bay mystery right now, but am following along and belong to Quiltville. Thanks for posting this info…I've bookmarked the link to the pattern printout pages! Thanks!

  5. Thanks for this tutorial. I have never used this before, because HSTs don't bother me that much, but I can certainly see where it would be great for a project like this one! Interstingly, I am currently working with the same musical note fabric. Why do you press the seams open?

  6. Okay. I've just got two random comments. 1. I LOVE the color of your nail polish! It's so pretty! 2. The music notes fabric is super cute! Btw thanks for the fun tutorial!

  7. Thanks for taking time to share. I am going to try this right now.

  8. Okay, Katie, One more question…..how do you attach the paper before you sew? Glue stick around the perimeter? It seems like it would shift if you didn't attach it somehow but I haven't tried yet. Tami In Denver

  9. @Nonnie – I liked this because the template was free to download and I could print it out on my own paper! I didn't have to order it from somewhere. Also liked I wouldn't get a fat quarter's worth of duplicates. I wanted some variety.

    @Scooquilt – Pressed open out of habit – oops. Bonnie suggested these seams be pressed to the dark fabric.

    @KnoxBlox – I didn't do anything special to adhere the paper – just pressed it before I threw it under the needle. The Carol Doaks paper seems to hold pretty well to fabric without shifting. If you find your paper is shifting I think a gluestick in the margins would be perfect to hold it in place.

  10. I’ve been doing this for years, using two fat quarters and drawing out my lines and gridwork.. I am so thrilled that you shared the printable ones here, now I don’t have to draw my lines. Perfect! thanks!

    • It saved me a lot of time! You get a little bit of waste from trimming but it goes so fast I think it is worth it. Glad you found it useful! Free is always for me :)

  11. Oh thank you so much! This is a great tip!!! Would love to always get perfect HSTs!!!

  12. that looks a whole lot easier than thangles!

  13. Carole Ann Wool says:

    I just decided to make a chevron baby quilt and came here looking for this, thanks so much! The site looks great!

  14. Great Article on Half Square Triangles….going to make Ocean Waves and this article is very helpful!


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