How to Make Half Square Triangles One at at Time

Quilting basics are a must whether you are just getting started or you've been quilting for a while. It's the foundation for making a good quality quilt, and I'd love to show you how to make half square triangles one at a time.

Put the Pieces Together

To make these half square triangles I have two different colored fabrics. If your fabric has a right side to it with some pattern or some texture or something with that you want to make sure to put those right sides together. Depending on what size you want your final pieces to be, I'd suggest cutting your fabric about 1/2" bigger than your final size. This gives you a little wiggle room if you're just starting out.

Next, we're going to match up those sides. Line your ruler up from corner to corner, but slide your ruler just off the points to keep your seam from shifting slightly. It's kind of like leaving a blade's width if you're cutting a piece of wood. Now you can mark your diagonal down the center. We are only going to get one half square triangle out of this, but if you're like me and you don't want to waste too much fabric, we can make a smaller half square triangle to use for another project. We want to leave ourselves about a half or a quarter inch away from our seam line and then a quarter inch away from our seam line on the next one. Put your ruler at the half inch mark on that line that we just drew and then draw another line on that side.

So now you can sew down both lines you marked, when you trim it down the center, you'll have two half square triangles, one that's a little bit smaller than you need. You can save that for a different project!

You can leave them folded in half once you sew them and then put them in a half square triangle bucket so you can use them later.

Let's Get to Sewing!

Using and open toe foot makes it easier to see where your needle is going and how everything is looking.

Stack your fabric together with the right sides together, and put the needle down in the top corner. Next, lower your foot and sew right down the line you marked in the center.

If your machine wants to eat your fabric, and sometimes it does that when we're starting in a point, then take a piece of scrap fabric, (I use my selvedge ends) and you can start sewing on that first just to get those thread tails up on top of your machine. Then sew it on the line. Make sure to leave that scrap fabric attached and your needle down. Then line up your line with your needle, making sure your fabric is still stacked nicely.

Okay, and then you can start sewing to help pull that piece of fabric through. If you have diagonal seam tape, it helps you to keep your seams lined up, and comes in really handy with these half square triangles.

If you have a lot of half square triangles to make, you can chain piece these blocks. Chain piecing helps save thread, time, and eventually money because you're not wasting a bunch of thread. Once you sew one block together, make sure to pull those thread tails out every single time you finish a piece. Keep your needle down, then sew right off the point of the next one. You can just keep doing this until you run out of pieces to sew. Once you're down sewing them all, you can clip the connecting threads to separate them all.

Now, let's set the seams which just means we're going to iron them flat right down that seam.

That just helps reset all those fibers back to where they should be after the sewing machine kind of scrunched them up. You can just layer them on top of each other. Just give them a quick press.

And now we need to trim all of our blocks a quarter inch away from our seam line. So here's the one that we sewed two little lines on, and you can set your quarter inch line of your ruler right on the seam that we just sewed and then we're going to trim a quarter inch away from that. So now you have a quarter inch of fabric on either side of the seams.

You now have two half square triangles! They're not the same size though. So put the smaller one in a scrap bin, full of half square triangles for later.

Having a rotary blade that is nice and sharp is a must. You don't want to use a dull one because it won't cut through this and you'll be pressing even harder, which can hurt your wrist.

The good thing about one at a time is if you're going through your stash of fabric and you just have a little piece of fabric and you want to put it together, you can still make these half square triangles one at a time.

Let's Iron!

All right, so now we need to iron these babies. There are several different ways we can iron them.

A lot of patterns say to press it towards the dark side, so put the light side of the fabric on your ironing board so that you can keep the seam flat. And as you peel the fabric over, the seam is going to rest on the dark side. And then we're just going to put this iron down on the light side and butt it right up against that seam and push it over. That way the seam is sitting on the dark side.

And look how beautiful those are turning out!

Another way to do it, and a lot of patterns are saying this nowadays, is to open these seams. That reduces the bulk of the fabric behind the block, so that when you do the quilting, you're not hitting bulky seams with your needle.

If you're going to finish your quilt on a domestic or on a long arm machine, it also helps keep the block the right dimensions. Sometimes when you iron it towards the dark side, just that little bit of bulk can help shrink your fabric just a little bit. Speaking of shrinking, do not use steam in your iron, or spritzing these with starch or water if you have not pre washed or pre starched your fabric.

Another really fun tool to use is called a cobbler's clapper. It's just a piece of wood that when you set it on your block, it helps absorb the heat from your block and helps set it nice and flat and crisp. And we all love flat, crisp blocks.

So we're just going to continue to iron these towards the dark side. Now ironing them towards the dark side can be helpful if you have to nest your seams at all. That way those seams can just lock in together, like they're giving each other a little kiss. And what I mean by that is, if we were going to put the dark to the light and the dark to the light here, you could, and those seams right next to each other would just kind of lock in place.

You can feel how smooth it is right there in the middle. If it's feeling bumpy at all, then just scoot it over just a little bit until those seams are right next to each other. This is very helpful when making other types of blocks

Time to Trim!

Alright, last step to making our half square triangle blocks is we need to trim these up to the right dimensions. Now, the quilt that I'm making, I'm going to make them at three and a half inches. So let's measure them. I'm going to put the diagonal of my ruler on the diagonal of my block. And they're measuring about four inches, but I want them to be three and a half.

So I'm going to take a little bit off each side. Keep the diagonal of your ruler on the diagonal of your block and hold that in place. Once you've pulled it down to the size you need, just trim off both sides using a little pressure and a smooth, straight line.

I hope that is tutorial was helpful, and you are ready to make your very own half-square triangles! If you're looking for a community of other quilters, make sure to join us for our next Journey Back Quilting Guild, held each month. You can find more info about it HERE.​