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Let's Make Half-Square Triangles

I am soooo excited about today's topic because I am super-fan of the Half-Square Triangle!! They are so versatile and I LOVE making quilts with them as you can see.

I am NOT a fan of cutting a bunch of small triangles and sewing them together, so i like to use multiple-make methods - either 2, 4, or 8 at a time. I outline several in my pattern and thought I would review some pros & cons of each method.

Make 8-at-a-time Half-Square Triangles

This method makes alot of HSTs really fast!

Put your fabrics right-sides (pattern-side) together. This goes for all methods. Be careful with tonal whites - they can be tricky!

Mark 2 diagonal lines from corner to corner using a pencil or disappearing fabric marker. There are versions that use water or heat to disappear. (I use Frixion pens which iron away.)

Then sew 1/4" away from your lines on both sides of each line.

The last step is to cut in half vertically and horizontally through your X. Measure but also look at where your drawn and stitch lines cross.

Then cut diagonally on the lines you drew. You now have 8 little HSTs!

4-at-a-time HST Method: 2 ways

This method is a little quicker, but makes half as many at once:

  • Put your fabrics RST (right sides together)

  • Pin in the middle to keep in place

  • Sew 1/4" all the way around the square

  • Cut each diagonal to make 4 Half-Square Triangles

Now I find that sometimes the HSTs are not equal. Two will be good and two will be off a little. So here's another way to do this method:

  • Place your fabric RST

  • Cut your diagonals first

  • Pin each edge

  • Sew each edge

I like this way a little better because your HST size is more consistent and you can chain piece which is faster.

Now I find that as long as I keep my pieces close together I don't have an issue with the front end getting sucked down into plate area, but if you do then you can also try a single-hole plate. My last tip for chain piecing triangles is to slow down at the end so your seam stays straight (sometimes the ends try to kick out a little).

The 2-at-a-time Method

The one thing about many block-making methods is that they require trimming which is not very fun, but necessary - like ironing/pressing. The 2-at-a-time method is good for more accuracy. If you don't like trimming, you can try this method.

The main issue here is the math, which I'm sure you can search for a chart for any block size. For the this pattern's options you make 2", 4.5", or 6.5" blocks, so you will start with 2-3/8", 4-7/8", or 6-7/8" squares. Make sure you count the number of blocks needed for each color so you can cut the correct number of fabric squares. This method will also cut down on the number of extras if that is important to you.

Other than that this method is very easy, see below:

HSTs - Foundation Paper Piecing

The final method for making Half-Square Triangles is using foundation papers like these 4.5" Half Square Triangle Paper | Triangles on a Roll #H450 | Fat Quarter Shop

This method is also great for accuracy and easy sewing because you just follow directions, sew on the lines, and rip away the papers after pressing and trimming.

Pressing and Trimming

When you PRESS use a light touch to use the heat and steam to flatten your seam. You want them to be straight too, so go slow and don't stretch the fabric by pushing down too much.

Typically HSTs are pressed toward the "dark side". I always press the seam closed first to "set" the seam, and then open it with darker color on top, so the seam stays under. This makes it easy to nest and keep your lines straight in your rings. However, this can make intersections very bulky when you join rows, so you can press any problem areas open. There are also places where the seams don't nest well, so you can press them to the light side entirely or only at the seam area. (I will share some more photos when it comes to sewing the rows together.)

Finally the trimming, this is my least favorite part (and main con) but you have to cut off the dog ears no matter which method you use. The blocks made in my Lovelight pattern are not very oversized, but do require trimming. A good ruler can make it go faster.

As you can see above, I am making 6.5" blocks and I have 6.5" square ruler with a diagonal line (VERY IMPORTANT). I love this ruler by Creative Grids, but I know many quilters who love Bloc-Loc and other specialty rulers for squaring up HSTs and other blocks.

When squaring up your HSTs you put the diagonal (45 degree) line on your seam and then trim off the extra on all 4 sides. When the block is smaller than my ruler, I always leave a little extra if possible and trim 2 sides. Then rotate, line up on your 2 trimmed sides with the exact size you want, and trim the other 2 sides.

Miscellaneous Odd & Ends

If you didn't use pre-cuts and you want some quick cutting tips, here is short video:

(This is an .mp4 so if you have problems viewing try watching on your phone)

Also if you want to make a Full-size, here are the changes you can do to make one. If you want to make a crib size, just make 12 rows instead of 14, and no borders from the Throw size.

Love-light Full Pattern Changes
Download PDF • 494KB

I hope these tips help you now and for future projects.

I am going to make some each day this week so that I don't get too bogged down with the pressing and trimming. I post updates on Facebook and Instagram, so follow me @polkadotpeepquiltsetc to see and add yours with #Lovelightquilt too!

If you have any other questions, please contact me in the comments, contact me page, or on social media.

Be Blessed & Happy Making!


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