Tip Jar: Half-triangle Squares

When I first started making quilts, I loved strip-piecing.  Nine-patches and four-patches, Irish Chains and Rail Fences – even strips that finished at less than 1″ didn’t seem that difficult.  I made a Sun and Shadow quilt, a Trip Around the World and a Lone Star – it was still strip-pieced.  But half-triangle squares?  Not. On. The. List.

The only thing my pieced units had in common with half-triangle squares is that they both had four sides.  Ninety-degree corners?  Yeah, right.  I was lucky if I could manage getting one that could be deemed to be a right-angle.

Then I learned that there was more than one way to make them and I was hooked.

So that’s the subject for today – half-triangle squares.


Edyta Sitar of Laundry Basket Quilts uses a lot of half-triangle squares – the quilt on the wall is Blue Spruce and the one on the bed is Frost.  Both are made with Cold Spell Prints & Batiks.

Not half-square triangles – though they are required to make a half-triangle square.  It’s been the subject of some amusement since I started working here because I have always called the square made up of two equal-size triangles a half-triangle square.  A half-square triangle is the single triangle part.  (And yes, I use the same distinctions for quarter-triangle squares and quarter-square triangles.  I know… I’m an odd duck.)

Whatever you like to call them, I think it’s important to know as many ways as possible to make them because you never know when you might need to use a different method.  Tools for the toolbox, right?

The “old-fashioned” way of making HTSs was to cut two squares 7/8″ bigger than the finished size you needed your HTS to be.  E.g., 3″ finished meant cutting two squares 3 7/8″ x 3 7.8″.  One light, one dark.  Cut the squares in half on the diagonal and sew the long side with a scant 1/4″ seam allowance.


Press the seam to the dark side and pray for the best.

Or maybe that’s just me.


This is Lisa Bongean of Primitive Gatherings‘ spectacular, award-winning Words To Live By quilt combining a squillion HTSs and wool applique.

Half-triangle square rulers.  Sewing two triangles together to piece the required size of HTS can also be done by using specific rulers to cut the triangles – a 4 1/2″ or 6 1/2″ Easy Angle or an Omnigrid 90-degree ruler.

Then it’s sew, press and presto – the finished HTS that measures what you need it to measure.

Using squares instead of triangles.  Somewhere along the line, some genius quilter got the crazy idea of not cutting the square in half to make triangles – instead a line was drawn on the wrong side of the “light” fabric and the fabrics were stitched a scant 1/4″ on both sides of the drawn line.


Cut it apart on the line and press the seams to the dark side.

The only thing you needed to know was the math of what size square to cut – finished size plus 7/8″.

Some rulers make it even easier, you don’t need to know the math.  The Magic Half-Square Ruler from Quilter’s Rule is an example.  Just use the lines on the ruler that correspond to the finished size you want to make and cut the squares.


Then use the openings in the diagonal center of the ruler to mark your stitching lines or the center-guideline.  Stitch, cut, press and done – the HTS is the right size.

There are a couple more options in the “draw the line” technique that I’ll talk about in a moment – we’re still piecing exactly to size here.

Triangle paper.  There are several different brands and types, and while they basically work the same way, there are some differences that might make one more preferable than another.


While I don’t use triangle paper often, it’s the best method when you’re making a lot of HTSs that need to be the same.  If you need 8 or more matching HTSs, or all your HTSs use the same background, triangle paper is absolutely the way to go.  At least that’s what I’ll be using.

Here are some of the different kinds:


  • Primitive Gatherings Triangle Paper
    • Because she does so many small quilts with little pieces, Lisa was the first to make a triangle paper specifically for 5″ charm squares.  The other triangle papers are printed on 11″ x 17″  and can be easily trimmed when only 4, 8, 12, etc. HTSs are needed.  Both are available in a wide range of sizes.
    • The paper is white, copy-like paper.  It stitches and tears off easily.
    • Lisa also does triangle paper kits for some of her “has lots of HTSs” patterns.
    • I used Lisa’s 2″ finished HTS paper when I made “Shamelessly Copying Jen”.  I trimmed the paper to a 3 x 3 grid – enough for 18 HTSs – and saved the remaining piece.


  • Laundry Basket Quilts Triangle Paper
    • Edyta has been making triangle paper for many years – if you made anything from her wonderful Friendship Triangles book, you’re probably familiar with her papers.  At Fall Market last September, Edyta introduced triangle papers specifically sized for Layer Cakes and Charm Packs.
    • The original paper was designed for use with a 21″ strip cut from a fat quarter or fat eighth.  But it can easily be trimmed if only 4, 6, 8, etc. HTSs are required.
    • Edyta’s papers are printed on a newsprint-like paper so they also stitch and tear easily.  I think these papers are easier to pin than some of the others – and yes, pinning the paper to the fabric is a good idea as it does like to shift as you stitch.


  • Spinning Star’s Star Singles
    • If I’m making blocks where I need eight matching HTSs, or I’m making a quilt with a lot of variety for the “lights” and “darks”, this is my favorite paper to use because it’s already sized for just eight HTSs.  Anything that makes life easier is a good thing, right?


  • Triangles on a Roll
    • This paper was created by two ladies who used to own a quilt shop in Phoenix, Arizona so this is the first triangle paper I used.  It’s still a terrific product.  It comes in a wide variety of sizes and can be trimmed to any length – multiple of 4 – that you need.  The paper is also thin enough that it is easy to pin, stitch and tear off.


  • SQangles**
    • SQangles get an asterisk because they really aren’t a triangle paper – they’re an iron-on printable that transfers the same grid used on paper to your fabrics.  There are no lines to draw or papers to tear.  I’ve used them a few times and if you make a lot of matching HTSs and don’t like the time or mess involved with tearing-off paper triangles, SQangles are a terrific option.
  • Ta-Da Triangles**
    • Another asterisk because Ta-Da Triangles are a pre-printed on a thin fusible interfacing that is adhered to the fabric.  As with SQangles, there aren’t any lines to draw or papers to tear.  There are approximately 2 yards of the printed interfacing in each package and while it is sized to fit fat quarters, it can be trimmed to fit Layer Cakes and smaller pieces of fabric.  It is simply a matter of cut, press, sew, cut and press.  (That sounds like more than it is.)
  • Thangles
    • If you have a lot of pre-cut strips – including Jelly Rolls – Thangles are great because everything is based on the 1/2″ and 1/4″ increments – not the 7/8″ measurement.

Trimming to size.  Finally, right?

If I’m making a lot of very scrappy HTSs, this is my “happy place” – it’s where I get the best results for me.

And where the little extra-triangles get trimmed off in the same step – those do need to be removed.  Always.  No matter what method you use.


I use the draw-the-line method and just add 1″ to the finished size of my HTSs. Some people prefer to add a little more – 1 1/8″ or 1 1/4″ – to the finished size but 1″ works for me because I always stitch them with a slightly-smaller than scant 1/4″ seam allowance to get a teeny bit more wiggle-room.  Trimming-to-size also works with other methods, a sweet friend and amazing quilter trims down HTSs that she’s made with an Easy Angle ruler.

What kind of ruler to use?  There are several – hundreds?

  • A regular, old-fashioned square ruler measuring 4 1/2″, 6 1/2″, 9 1/2″, etc.  I like the Olfa Frosted 4 1/2″ x 4 1/2″ ruler.
  • Bias Square Ruler from That Patchwork Place.  This ruler is designed for trimming HTSs and if you make anything that needs “finished” HTSs in 1/8″ sizes – e.g., Feathered Stars – this is a terrific choice.
  • Itty Bitty Eights by Lisa Bongean for Primitive Gatherings.  I love these rulers with their 1/8″ markings.


  • Bloc-Loc.  When the first Bloc-Loc rulers for HTSs came out, you needed a different ruler for each size HTS.  That didn’t seem very practical to me… and my regular Olfa was working just fine, thank you.  Then the Bloc-Locs got regular ruler-markings and it was all over – I fell in love.  Swoon-city!

Quilters who don’t like trimming-to-size usually cite one of these reasons – it takes time, it wastes fabric, and an accomplished quilter-sewist should be able to piece things exactly to size.

Does it take time?  Yes, but I think this is so much of a personal preference.  It’s odd but I like the repetitive nature of trimming half-triangle squares – and flying geese.  I can be listening to an audio book or something on television and it goes more quickly than you’d think.  And trying to fight a block that isn’t square because one or more pieces isn’t square is more frustrating.

Wasting fabric – this is another one of those “yes, but…” questions for me.  Many years ago, I was asked during a presentation about making flying geese.  When I replied that I trimmed them down using one of the new-at-the-time rulers, the lovely lady who had asked the question replied that trimming wasted too much fabric for her.  I was showing a quilt at the moment made entirely with flying geese – stars and a flying geese border element – and had written the pattern for both no-waste and the ruler-of-the-moment methods so I knew how much additional yardage was involved.  An additional 3/4 of a yard was required.  But for argument’s sake, I said let’s say it was twice that amount, 1 1/2 yards.  And I would price the fabric at $10.00 a yard – higher than the $8.50 cost at the time.  (I did say it was many years ago…)  The “waste” was going to cost me $15.00 – and for that, I was “purchasing” square blocks and a flat, straight flying geese border strip.  I get that it can sometimes be a significant expense but I think we make those decisions based on several factors.  To get the best possible results, I do better with trimming some units down to size.


(Just so you know, the lady who asked the question laughed and said “well, if you’re going put it that way…”)

As for the notion that I should be able to piece things exactly to size… my first inclination is to say “whatever”.  But I do agree with the point – mostly.  Do I know how to cut carefully, stitch with a perfect scant 1/4″ seam allowance and then gently PRESS my units so that they are flat and square… meaning, not distorted?  Yes.  But all that time I save by not trimming things down… I’m spending going really, really, really slowly.  Knowing how and putting that knowledge into practice are two entirely different things.

No, being a quilter does not mean that you are a patient person.  I am Exhibit A.

For more tips and tricks about making any kind of pieced triangle unit, I recommend checking out Pat Sloan’s latest book – Teach Me To Sew Triangles from Martingale/That Patchwork Place.


In addition to showing several methods for half-triangle squares, the book includes methods for quarter-triangle squares and flying geese.


And some really pretty projects.

That’s it for me today!

(The two winners of the All-In-A-Row books and Layer Cakes has been notified via e-mail.)

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47 thoughts on “Tip Jar: Half-triangle Squares

  1. I didn’t realize there were so many different triangle papers out there! I make HSTs as leaders/enders from scraps when sewing, toss in a basket, and use TV time for squaring them up. One of these days I’ll make friends with my Easy Angle ruler for a project. Thanks for the great info and tips!

  2. Thanks for another informative and enlightening tutorial, Carrie. I, too, had no idea there were so many different papers available (that’s what you get when you live so far from the heart of quilting stores!) – but when I get to the US this spring, I’ll know exactly what I want to purchase…(thanks). Like you, I trim my HSTs and HTSs down – find it gives me just that exactitude that makes a block come out just a bit better. Love your quilt with the flying geese border, too – beautiful!

  3. Wow! What a great overview. One other option – it becomes a paper tear away method, is Triangulations by Brenda Henning. It is a CD that allows you to print your own tear away grid. I use regular computer paper and with a small stitch it then tears away easily. It has sizes from 1/2″ to 7 1/2″ in 1/16″ increments. Also has quarter square triangle foundations and Flying Geese. Great when the urge to create strikes and your quilt shop is not open or you don’t want to wait to mail order specific papers.

    1. Triangulations! I did forget about that one – and I think I used to have that CD. Old age… memory… I’m going back to bed. 🙂

  4. Don’t forget sewing two strips together and cutting the HST that way (ala Marsha McCloskey). No bias on the edge. Or the Missouri Star method of sewing all the way around two squares and cutting them on the diagonal. I have enjoyed using both of those methods. Camille uses the second method in her Round and Round pattern. I too like to trim HST units using the Bloc Loc rulers. I am looking forward to trying their flying geese rulers in the future.

    1. I was going to mention the bias-strip method with the ruler but I didn’t want to have to make bias strips for a picture. lol Did you like that method? I confess that even when there were so many fewer options for making a lot of HTSs, I never cared much for making them that way.

      As for the Missouri Star method that Camille used for Round & Round, I think it’s a “good to know” way of making HTSs but also not a favorite. (Am I being really picky this morning? lol) I made Round & Round twice and made my HTss a different way both times. 🙂

      1. Love triangle papers and Bloc-Loc rulers. FYI, I use a dab of a glue stick when doing triangle papers to avoid shifting and pin distortion. I, also, print my own triangle papers using Print & Sew’s Triangle Magic to create any size HTS sheets I need.
        Thank you for your wonderful HTS/HST info. BTW, the use of starch needs to be encouraged for anyone using the MSQC Jenny Doan method which produces all bias edges. A very doable method if starch is your friend.

  5. Wow…I am in the “didn’t know there are so many triangle papers” camp. I have used Thangles and Triangles on a Roll, but the others are new to me. That said, I generally do either the “draw a line” method or the Jennie Doan “sew around two squares and cut on both diagonals” method that leaves you with 4 bias edges. Those both work nicely for me.

    1. Shhh… I think triangle papers are great but even when I’m making eight-matching, I do the “draw the line” so I can trim them up. 🙂

      I think the “Jenny Doan method” is a great method to know – sometimes it’s the only way to get the pieces you need in the size you need from the fabric you have. My only quibble with it is that it’s often taught without at least some mention of the bias-edges. For many of us, that’s not even a speed-bump on our quilting road but for beginners or quilters who didn’t take sewing in home-ec, there can be some unexplained wonkiness. 🙂

  6. Great article. You can learn something new each day. Very interesting about the terminology, HST and HTS. Thanks for all the tips.

  7. Amazing – now I know why I’ve never made HST. Sounds scary, but with all your great tips, I just may need to give it a whirl. Thank you for a very informative post!

  8. I do like the Block Loc rulers for squaring up. But being older and entrenched in my habits, I just make my HSTs slightly bigger than needed and then trim them up so they are perfect while listening to TV or some such. If I am going to make a quilt, I want it to be perfect.

    1. Gee thanks, Sue. I think you just called me old! lol Ditto to everything you wrote – though I will own-up to being “stubbornly entrenched in my habits”. (If he reads this, I expect “aka Golden Child” will agree.)

  9. I was just like you when I started quilting – no HST for me! Everything was strip pieced. I avoided triangles like the plague. I like drawing a grid directly on the fabric when using fat quarters or making identical HST’s. I think it’s more accurate and there is less shifting of the fabric and I hate tearing off paper when paper piecing. There are stencils sold by Sunday Best Quiltworks that allow you to stencil the grid on the fabric using a chalk pouncer or marker. I’ve bought the stencils but still haven’t used them. They are pretty inexpensive. (If I’m only making a few, then drawing a line on the back of a square and trimming down works for me.)

  10. I think they’ll always be HSTs to me, some habits die hard. But I’m a Easy Angle girl and I cut my strips 1/8″ wider and square them to size. HSTs, HTSs, regardless of the name, they’re my favorite block to make! One of my favorite pastimes is to watch the pile of trimmings grow, it’s a nice little preview of what the finished project is going to look like. I did not know Bloc Loc made a one size fits all ruler, thanks for the info!

  11. I always learn something here, but this was a bonanza of info. I think I will venture into triangle papers ’cause I yearn to make one of those Tree of Life quilts, Thanks for all you do to entertain and inform us. I read this blog every day and am never disappointed.

  12. I love Bloc-Loc rulers!! They are worth the time and extra fabric if you want perfect squares and points to meet!!

  13. I use a variety of methods to make HSTs – depending on my mood. Sometimes I do want to be increase my skill level and make them “correctly” without having to trim. My hope is that over time I will be so adept that I won’t have to go slowly. Other times, I don’t have the patience or mood to cut and sew that carefully and make them bigger, but of course, then I have to have the patience to trim them.

  14. Die cut machines are another awesome way to cut half square triangles. I used the Accuquilt Baby Go and can cut quickly and accurately…no squaring up and no dog ears to trim.

  15. Great over view for working with triangles, and rulers to make them. My question is, can left-handers use these rulers?? Some rulers are hard to figure out when, to the ruler, I am using it backwards. Any thoughts, on which rulers work for those of us on “the other side”.

  16. This was such on informative post, thank you so much. It seems there’s always something new to learn…

  17. This post is so informative!! You give detailed descriptions of all the options. To correlate all the options with distinct explanations takes time and critical thinking skills. I will definitely keep this post for future use. I have just finished 42 pinwheels [Heart’s Content] . Will try some of these other options next time.

    Yes, to the other post, you can use the Accuquilt cutter which works well with solids, but you have to be very careful with your fabric choices. For example, polkadots, one way designs, etc.

    Enjoy your posts!!

  18. I’m with you! I cut my HSTs a bit bigger and then trim them down. If I’m making bigger HSTs (let’s say at least 2.5″ finished) I clap the square in half and press lightly with my iron. This method doesn’t work so good if the square is small but for bigger squares it’s an easy and fast way (spares the trouble of drawing a line;-) I’ve never used papers don’t know why I should spend the money when there’re a lot of other ways. BWT I use my Omnigrid 8.5″x12″ ruler to square them and it works perfectly!

  19. I’ve used Thangles once and wasn’t overly thrilled. I prefer to trim down my pieces to make them just right. However reading this post and all of the comments I suddenly feel like quite the novice!

  20. And if you don’t like drawing lines at all, the Clearly Perfect Angles have been a proven winner. Scant seams are easy with this template, too!

  21. I have a lot of triangle papers in my plastic bins. I didn’t used to make blocks with triangles much before 2015 because of the triangle yucks… Did the block of the month with Pat Sloan and another with Michele Foster in 2015. Now comfy with triangles. I think I have tried most of the paper styles except some have changed names/company owners.

    Mimi ??? who used to work with Mary Ellen Hopkins (in ancient times) had a lovely triangle paper that came on newsprint in a gazillion finished triangle sizes. I liked hers because you could cut a sheet down to 8.5 x 11, or use the full sheet if necessary and it was very easy to handle in the sewing machine. It also made very accurate triangle blocks or block units. Mimi sold the company to someone a few years ago and I’m no longer sure what brand they are currently sold under.

  22. I LOVE LOVE the Stella Blue pattern. I made it King size for a young man who loves Camo everything. My version is green and brown. It was a college graduation gift and is much treasured by him. Thanks for a great post on HSTs.

  23. I also trim down for accuracy but I recently started trimming the triangles before I press them open that way I don’t have to move my ruler. I know there are rulers marked for this but I usually just run a piece of tape along the ruler at 45′ degrees at the proper finished dimension so I can align right to it and trim around the corner (so to speak). Hope that made sense…

  24. Hullo from Australia – thanks so much for this-we emailed re this a short while ago and am so happy with all the variations to try, very educational and it doesn’t matter what method you use, there will be a favourite that suits. I have yet to try paper method ( but I will try one out ) , still enjoy the cut square and draw diagonal line, feel this is relaxing to me. Thoroughly enjoyed the article

  25. wow ..thanks again for the great post! I think I have tried most of these methods and my current favorite is the easy angle ruler. I think I will go cut up some stash into half square triangles on this very snowy beautiful day:) oh, trimming with Eleanor Burns ruler before pressing open is awesome for all those “trimmed” off triangles from projects!!

  26. What a great and informative post! One method/company I didn’t see was Triangulations by Brenda Henning. ( I don’t know her personally and have no kickback from this comment) This one works for me because I live in an area without a quilt store and when I want one of the products mentioned above I have to drive over 2 hours to get them. Someone suggested Triangulations to me and I thought it was worth a shot. It is a CD/program that allows me to print off 1/2 sq triangles in from 1/2″ to 7 1/2″ in 1/16th increments. Not only that but I can do 1/4 sq, and flying geese as well. It is formatted to print on regular printer paper and I can print as many or as few as I need. Works for me!

  27. Eleanor Burns’ triangle trimming ruler is sheer genius. You trim the HST’s before you open them up, and you’re trimming both sides at the same time.

  28. Thank you for all the wonderful tips on the HST. I did not know there were so many choices out there.

  29. Carrie, this was an awesome post about HSTs. I’ve printed it out (pictures and everything … especially Lisa’s gorgeous quilt) so I’ll remember everything.
    Also, I was reading some of your past blogs and saw a quilt you showed in your Aug 28, 2015 blog (unfortunately I couldn’t copy paste it here, but it was the last photo shown). What is the name of the pattern? It is too cool! Thanks for your help!

    1. Hi Gail – The last quilt pictured is by Samantha Dorn, it’s her Bonnie & Camille sampler. There isn’t a pattern for the quilt, she essentially made it up as she went along. The blocks come from Thimbleblossoms patterns – the inspiration was an “orphan block” sampler quilt that Camille posted a year or so ago. 🙂

  30. Hi, I’m a lefthanded quilter and you don’t need left handed rulers. A ruler has two sides and I just place my fabric with yardage to the left of my ruler.

  31. Have tried many of the techniques including the bias strips Love my die cutting machine cuts perfect sizes. The ease and precision of the die cut pieces are worth the price!

  32. I just heard about a thing called Clearly Perfect Angles. I think I will try that method. Seems like a lot less work to me. I don’t enjoy trimming, and don’t like the waste, but I do agree the perfectly cut HST’s are soooo nice when you’re done. If I could just get the perfect scant 1/4″ down again (after changing to Aurifil thread it seems to be illusive again), I think the Clearly Perfect Angles would work best for me. I’m glad there’s so many versions – something for everybody.

    1. Oh, hate wasting paper, too. Remember when the “paperless” movement started? Whatever happened to that…I say as I’m about to try foundation paper piecing for the first time. ;oD

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