Wednesday, March 25, 2015

How To Make The Perfect Half Square Triangles

Hello sweet Chickadees!
Hope you are enjoying your week so far?
I was making some half square triangles (hst) over the weekend and wanted to share how I make them with you.

I stared with my 6 1/2 inch Creative Grid ruler
 3 1/2 inch dark and light squares (one of each)
Fons and Porter Quarter Inch Seam Marker, you can find them at JoAnns's.

With right sides together line up your quarter inch seam marker point to point on your 3 1/2 inch squares.

Draw a line on either side of your ruler.
I used a Frixion pin by Pilot.  You can find these at any office supply store and when you go to press the line will disappear.

Now you are going to sew on your lines.

Using the diagonal line on your ruler, line it up so that it is point to point on your block.
Using your rotary cutting cut down the middle.
This will leave you a 1/4 inch seam allowance on both sides.

You will now have 2 triangles.

I always set my seams on the dark side, this makes it easier to press it open to dark side.

Use the diagonal line on your ruler and line it up on the seam.
Trim using your rotary cutter.

This is how you block will look.

Turn your block around.
Use the diagonal line on your ruler, line it up with you seam and the 2 7/8 inch mark on your ruler.
Trim using your rotary cutter.

This will leave you with a 2 7/8 inch HST.

What I think the trick to making the perfect HST, is to cut your squares a 1/2 inch bigger and use this method.  Mine come out perfect every time.

Hope this helps you.

Happy Sewing.



  1. Hi Donna thankyou so much for this tutorial i will come back and try this out next week,you are so generous to share xx

  2. Thank you, I made pinwheels and several of my HST were a little wonky. I'll try this method next time.

  3. Oh, how I wish I inherited my mother's amazing love of quilting and sewing. You are always inspirational even if I can't stand to pick up a needle, Donna.

  4. Thanks for sharing sweet Donna! Hope you are having a fabulous weekend! xo Heather

  5. I have pinned you easy perfect half square triangles. Thanks my dear.

  6. Ok, that Fons and Porter thingy is going on my MUST BUY list!!! I'm going to try this next time, thanks!