Half Square Triangles (HST's)

Half Square Triangles (HST's) are a staple in quilting. Used on their own or within a traditional block, they are invaluable to creating many designs, and, as an added bonus, are very simple to make.

***scroll to the bottom of the page for a printable PDF

The first method to learn, especially good for the newbie quilter, is the 2-at-a-time HST's. These HST's are perfect for using up all the small bits of fabric in your scrap bin while making some wonderful scrappy quilts.

For demonstration purposes (and because that's the size I wanted for my “planned” scrappy quilt) we'll be making a 3” finished HST. Technically, cutting two squares at 3 ⅞” should work for two 3 ½” unfinished HST’s...but not everyone is careful about a perfect ¼” seam allowance so I prefer to cut my squares at 4” and then trim them to size later (the actual formula is to add ⅞” to the finished HST size required).

I call it “planned” scrappy because one side of the HST is the same in all units (Tula Pink's Seed Stitch in dark grey) while the other side is a mix of brightly coloured scraps and fat quarters.

Draw a diagonal line on the wrong side of all the brightly coloured squares (or use diagonal seam tape). Stitch ¼” from each side of the line, cut along the drawn line, and press seams toward the dark fabric or open...strictly personal choice. I'm lazy so I press to the dark side because I don't want to take the time to open the seam and press.

The units now need to be trimmed to 3 ½”...that includes the necessary ¼” seam allowances...so the actual HST will finish at 3”. Take advantage of the diagonal line on the ruler, line it up on the seam to trim the first corner square. Turn the square around, place the 3 ½” mark from the ruler on the previously trimmed corner and trim the opposite corner.

With my HST project I also opted to use Triangles On A Roll because I had multiples of the same colours being used. This way 8, or 12, or 16 (or more) HST's of the same set of fabrics could be cut at the same time...time saver! Just cut the paper on the roll for however many HST's needed for those fabrics and Bam!...done in no time. This method is perfect for a quilt that has multiple blocks of the same design using the same fabrics in each block.

Place two fabrics right sides together, pin the paper on top, and stitch along the dotted lines. This can be done in one continuous line of stitching, just follow the arrows...so satisfying! Then cut along the solid lines, remove the papers and press the seams. As you can see from the photo below, I was able to make 8 at a time from the two fabrics chosen. If you want to take the time and draw lines on the wrong side of the fabric instead of using triangle paper, it eliminates the paper, but there’s still the time involved in drawing the lines…your decision.

Sharon's Hint: When using triangle paper adjust the machine to a shorter stitch length...this perforates the paper and makes it easier to remove.

You might want to take a pair of scissors and trim off the little “ears” (where the awl is pointing in the photo) because they sometimes shadow through the top fabric, especially if a light coloured fabric is used.

HST's are so versatile and can be found in many traditional blocks. My student, Maritta, asked for some guidance recently. She found a quilt she liked that highlighted the Sawtooth Star block, but is a relatively new quilter so she wasn't sure about how to make it. After a couple of back and forth emails with some hints from me she took the plunge and made a sample block. I think it turned out great! She even added cornerstones and sashing.

You will notice that there are two areas highlighted. The white box shows how this Sawtooth Star block is made using HST's, but it can also be made using flying geese as is shown by the yellow box. If you already have multiple HST's sewn they can always be made into flying geese units.

For more quilt blocks using HST's all you have to do is an internet search for “quilt blocks using half square triangles” and you will be inundated. I've found a couple that are easy and quick to make that you might want to try. This wonderful 8 Pointed Star from scrapish.com, a super simple Friendship Star variation from The Crafty Quilter, and the Dutch Windmill pattern from maryquilts.com are just a few of the quilt blocks that can be made using this versatile unit...not to mention all the free seasonal blocks that can be found here on the Quiltish Corner website under tutorials. You’ll be able to get lots of HST practice!

There's always so much to learn in order to build your skill set. This is just one more useful technique that you can add to your quilting repertoire. Try it out!