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How To Piece Like a Rockstar – Part 2 – Make Better Half Square Triangles

This post has been edited to add in this video on 10/12/17.


I want to start this off my saying that you are making a quilt. The little things really don’t matter. Like if your points line up, or if your edges are wobbly, or if you have a pinch or two in your quilting. These little imperfections are okay. You are making something with your hands.

The whole idea is to enjoy making the quilt, or snuggling up under the quilt or even giving the quilt to someone you love.

It’s not to beat yourself up about.

So relax, shake off the pressure, it doesn’t REALLY matter.

No quilt policing goes on here. And for heaven sakes, if you see a quilt where the points are cut off or the seams don’t match, do not announce it to the quilt maker. It’s just plain mean.

That quilter just finished making a huge labor of love. That is a job well done. Lopsided blocks and all.

Quilting is my therapy, I don’t want to follow rules, so don’t.  Make your quilt and be happy doing it.

When I first started quilting, I was a piecing nightmare.  Who cares?  I just finished a quilt!

But then, after you have made many quilts, when quilting is something you do on a daily basis, when those half square triangles aren’t quite triangle or the very worse when you have made twenty blocks and half of them are off by a half inch and you desperately and creatively sew them together anyway, wash your quilt, and then find out that all your seams have split open. THAT is the moment when you realize that if you had just taken the time to press your seams open, if you had just spent a little more time making sure your 1/4″ seam was accurate, your quilt could have come together with less headaches on the way and not riddled with split seams after a few washings.

We are not going to call them rules. Rules are not for art, and quilting is an art. We are going to call them guidelines.

Guidelines that will not only give you pleasure at seeing all your hard work look as close to perfection as the human body can make (nothing is perfect) it. But MOST importantly, that everything comes together easily and almost effortlessly. Following just a few simple guidelines will make you not hate quilting or sewing.

You will never say, I’m done, nothing I ever do comes out right. You will never say, I can’t do this. You will never finish twenty blocks and some be distorted so you throw them in your closet never to see the light of day again and all your time and effort wasted.

Never again.

In this series we will cover:

Better cutting methods

How to make half square triangles

Nesting seams and pressing tips

How to make flying geese

Making the most with your mistakes

In this post, I’m going to show you how to use the Half Square Triangle (HST) Quilt in a Day ruler and how to make HSTs.

Half square triangles are VERY popular in quilt blocks.  And not because we all like them (though we do), but because some designs just need a triangle to make it work.  If you are a quilt maker, you will find yourself making HSTs often and since we use them so often, you need to know how to make them correctly.

There are MANY different ways to make HSTs, and you should choose a way that you like best.  You are the person who has to make them and all.

A few helpful notes:

1.) Once you have your HST made, it’s cut on the bias.  What does that mean to you?  It means it warps easy and can change it’s shape.  If you stretch it, you may find that your finished quilt block made with your stretched HST looks a little skewy.

2.)  When you press your HST, DO NOT iron it.  Do not run your iron across it the way you would do that snazzy blouse you like to wear.  This will warp your block. Instead, lift the iron up and set it on the block, lift it up, set it on the block. Do this until you are happy with it’s flatness.

3.)  I like to starch the heck out of my HSTs.  With a few exceptions, they are the only blocks I starch.  I started using starch because of these little devils. Once you starch it, I have found it no longer changes it’s shape.

4.) Pressing seams open.  Most of the time when I’m making a quilt block, I don’t press seams open. I press to the side I need to get my seams to nest.  However, when it comes to HSTs I ALWAYS press my seams open.  When I press to one side, my HSTs always warp and become skewy.  So, I have my HST face down, I open the seam with my fingers, I gently move the tip of the iron across my seam just to get it open (NOT TO FLATTEN), and then turn my HST right side up, starch, then press.  Note: I do this step in batches, so that when I starch I’m not just doing one block at a time.  This will speed things up a bit for you as well.  Open 5 or so seams, flip them all, starch them all, then press them all.

These four notes above completely changed my block accuracy skills.  HSTs were what was giving me trouble in my block accuracy, so I started taking my time more, doing the above notes and all of a sudden accuracy was upon me.

How to use the HST Quilt in a Day Ruler

So this ruler might be the best money I’ve ever spent on a ruler.  Plus, it doesn’t cost much.  Plus, plus, it works for 12 different size HSTs.

One side is HSTs on whole numbers, the other side is in 1/2 inch increments.

It’s easy to use.

So here is a ‘wanna be’ HST.

Go ahead and cut on your drawn line to make it into two HSTs.

Now this is before anything has been pressed.  Don’t press yet!

We have our two HSTs.  Line up your ruler to the size you want your unfinished HSTs to be.

I want mine to be 3.5″.  Line up your dash 3.5″ line on your stitch line.

a couple of close ups so you can see the dashed lines of the ruler, lining up with my stitch line.

Press, down on your ruler firmly and cut the two sides.

Now, I like to go ahead and cut my tails inward here, but if you wait until after you press you will get a more precise cut.

I do it here because I’ve gotten pretty good at eye balling it.

Now go ahead and press your seams open and you have it.

Complete and full instructions to make HSTs are up next.

How to Make Half Square Triangles


Some thoughts on HST math

An unfinished quilt block is a single quilt block that hasn’t been sewn into a quilt yet.  It’s just a block.

A finished quilt block is a block that is one of many blocks that has been sewn together in a quilt top.

If you are wanting 12″ finished blocks, you know that you need to make your blocks 12.5″ to achieve that.  This extra half inch allows for your 1/4″ seams.

On HSTs…

You have to add an additional .5″.  So let’s say you wanted 3″ finished HSTs.  That means you will need them to actually measure 3.5″.  But it means that you need to cut your beginner squares 4″.

So… 4″ squares, make 3.5″ unfinished HSTs, which make 3″ finished HSTs.  Got it?

This is the same for any number under the sun.

You might find that some patterns will have you cut your squares for HSTs on the 7/8″.  More power to people who do that.  It cuts out the need for the HST ruler and means no trimming.  However, without the trimming down step, I have found that my HSTs never end up the correct size.  For me, anytime I’m working with a pattern that tells me to cut my beginning square to 3 7/8″ and then make a HST, I usually go ahead cut it at 4″ and then trim down like the way I’ve taught you here today.  But you should do it the way that suits you best.

I hope you have enjoyed this installment of How to Piece like a Rockstar!


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  1. I am just starting to quilt and have found your instructions about half square triangles brilliant.
    I always wondered how to get a 4 inch half triangle square and you have made it so easy to work out….Just cut it 1 inch larger…..how simple!!
    Thank you

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