have been making a lot of quarter square triangles lately for a variety
of different projects, so I thought it might be good to share my
favorite method for making these versatile blocks.
With this method there isn’t any reason to create the quarter square triangle
block using triangles–by using square pieces of fabric you eliminate much of the trouble created by using working with the bias edges of triangles. And, what’s even better is that this method can be adapted to any pattern.
Step 1: Figure out the size squares you need. To make 4 quarter square triangle blocks, start out with four squares of fabric that each measure 1″ larger than the unfinished size of your desired block. So for a 4″ unfinished block (3 ½″ finished) you’ll need squares 5″ x 5″.
For this tutorial I’m using 4 different fabrics and creating quarter square triangle blocks that contain each of these four fabrics; however, this method works just as well for two-color or three color quarter square triangle blocks.
Step 2: Begin by placing two squares right sides together. Next you will draw a line diagonally across the back of the lighter block. Sew ¼″ on either side of your line. In the photo above, my diagonal line doesn’t show, but I went over the stitching lines with a pen so they’d show up better.
Step 3: After you have sewn both seams ¼″ away from the center, cut in half diagonally on the center drawn line.
Step 4: Each pair of squares will give you a pair of completed half square triangles. Press toward the darker fabric. Make sure you press carefully and be sure to press again on the front side to make sure that all of the seam is pressed neatly with no puckers or bubbles. We’re half-way there!
Step 5: Now, place two half-square triangles together again, right sides together. “Nest” the seam allowances. To nest seam allowances, butt the seams right next to each other. The seams should smoothly nest together with no gaps in between. It’s important not to have any gaps in between the seams so that everything will match correctly in the center of your block. Draw diagonal lines down the center and again sew ¼″ on either side just as you did in step 2 above.
Step 6: Again cut the blocks in half on the diagonal. Each pair will give you 4 quarter square triangle units.
You now have 4 beautiful quarter square triangle blocks, but there is one more step to finish up.
Step 7: Next, use a ruler with a diagonal line to trim your block to the exact size. Any square ruler the same size or larger than your block will work; however, I prefer the “Fit to be Quarter” ruler by Monique Dillard. I’ve used a variety of other rulers, and the reason I like this particular ruler the best is because there are additional markings which allow you to easily trim the blocks to any size up to 6 ½″ x 6 ½″ in increments of ¼ inches–with no guessing. Most other rulers only give you the option to trim every half inch. Also, Monique also makes a larger size ruler which will trim quarter square triangle units up to 9 ½″.
To make trimming easy, line up the diagonal line on the ruler with the diagonal seam of your block. Make sure the mid point line is in the correct place. You will notice that this block will be 4″ x 4″ unfinished, so the 2″ line goes right through the middle of the block where the four diagonal seams intersect.
Trim the right side and top, then flip your block and trim the other two sides. Always make sure the diagonal lines on the ruler match up with the diagonal seams on your block.
Now you’re finished! You’ve created four beautiful quarter square triangles with minimal bias to worry about!
Edited: You can also watch my video tutorial above which illustrates more clearly all of these steps!
Thanks so much for stopping by!
Great tutorial, thank you!
Thank you for your great tutorial…I LOVE your blog and read it
every time you post…….Janet (fan from Canada)
Sherri I just want to thank you again for teaching the "SHINE" class at Quilted Works on Friday. have read your new book Fresh Family Traditions from cover to cover, and loved it. Would have liked to see the your great grandmother's Chocolate Mayonnaise cake. I have never heard of that before. My grandmother always gave the married grandkids net dish cloth's loved them would like to know how to make them along with something she had bottled, jam, pickles etc. Brings back lot of memories. Almost have all my quilt block finished. Thanks again. Oh, yes I think my next quilt will be Emma's Bear Paw.
Angela Smith says
Thanks so much for this tutorial, I will definitely be trying this.
Michele T says
I like this method!!! Thanks for the tutorial – it is very helpful!!
Thank you for this great tutorial and pictures. I'll be brave enough now to try quarter square triangles!
It's a great way to make QSTs accurately. Good post!
Angie Burrett says
A really great tutorial – I am off to try it out. Thank you!
I love your tut's. Thanks sew much !
Elizabeth and Gary says
Such fun fabric! I love your color choices..I have been making triangles too for the quilt I have been working on.
I have enjoyed visiting with you today.
Have a sweet day, Elizabeth
Audrey Matlock says
Thanks for this great tutorial! Love your fabric choices too 🙂
Sherri I love your blocks especially the colors. Did you by any chance receive my mailing address?
Great tutorial! Thanks so much for sharing. Love the fabric too! Is that a Bonnie and Camille line?
Angela @ Cottage Magpie says
This is my favorite method, too. And those are sooo cute! Love the fabrics! ~Angela~
Thank you for this. I love the Fit to be Quarter rulers too! They make is so much easier to line things up.
Diana Holmblad says
I make the half square triangle with four squares the same way up to the first diagonal cut. Once you have two-color half square triangles you can put the squares right sides together and sew all around the outside. Then cut the diagonals and you have your four-color half square triangles without so much sewing. Hop I explained that well enough. Jenny, from Missouri Star Quilt, has a tutorial on You tube showing this. Thanks for your tutorial and I love your fabrics.
Do you have any tips for how to press the seams so that when you sew the completed blocks together the seams can nest? I happen to have just put together a few qst together and I'm trying to join them but I find that I'm getting a lot of bulk in the corners because I can't figure out a way to press the seams so all of them nest correctly! Thanks!
larriclaire quilty says
Thank you for this tutorial. I've been looking for this answer for several years. Farmer's Wife Quilt Along brought me to your informative blog.