The humble half square triangle (HST) is one of the building blocks of quilting. You can create endless shapes and patterns using these little squares! I love being efficient and making multiples of quilting elements to save time. Today we are going to make eight at a time HSTs!.
Pssst: This is the method used in our FREE Playful Placemats pattern. You can download that freebie by signing up for our newsletter.
You can use this method to make 8 HSTs of any size. Use the chart below to determine how large to cut your squares. Right click on the chart to open it in a new tab and print a copy for reference.
I'm going to make 3.5" HSTs (3" when sewn in) so I cut my blocks 8.25" square. I strongly recommend cutting the squares oversized using the column on the far right. It is hard to get an accurate HST when sewing so many at once.
The first step is to take two different coloured squares and place them right sides together. The colour combination is up to you! You will end up with eight of your chosen combo.
Mark two diagonal lines across the top square, from corner to opposite corner and again using the remaining corners. I like to use my Clover Hera marker here, but you can use fabric marker, chalk, or a pencil.
Sew four lines of stitching, 1/4" on either side of the diagonal lines. No need to backstitch at the start or end of each line. Try to be as precise as possible with your seam allowance here.
Lay the block flat on your cutting surface. You can press it flat if needed. Use a rotary cutter and quilting ruler to cut along your diagonal marked lines. Do not shift the fabric out of place while you are cutting.
Next, cut along the horizontal and vertical center lines. You can use your quilting ruler to find the center and ensure you are cutting in a straight line.
You should now have eight individual pieces that you can take to the ironing board. Gently peel the HSTs open and dry press before adding steam. Avoid pushing the edge of the iron into the diagonal seam as this will distort the HST. Press the HSTs with the seam allowance to one side or open, your choice. If using a pattern, check to see if it specifies a pressing direction.
Now we have some wonky looking HSTs! Time to trim! This is an essential part of the quilting process. It is especially difficult to make perfectly square HSTs when sewing multiple at a time.
Place your trimming ruler on the HSTs and line up the diagonal seam with a diagonal line on your ruler or diagonally across the inch markings. Ensure the desired trim size fits inside the HST and trim any excess on two of the four sides. Rotate the HST and align the trim size and diagonal line again. Trim the excess on the remaining two sides.
Trimming does take time but you will get faster, I promise! I trim four at a time on my rotating cutting mat to speed things up.
And that is how you make 8-at-a-time HSTs! Have fun playing with these versatile quilting blocks. Check out our free 24 HST Placemats pattern for a fun project! Let me know if the comments if you have any other tips to share.