a nice pile of HSTs ready to be trimmed
In preparation for piecing our blocks for our Chasing Chevrons quilt along, I decided to work ahead and show the three different ways that I make half square triangles {HSTs}. Each way has both pro's and con's and in the end, the method you use relies the most on your cutting, piecing and pressing accuracy. By rolling this tutorial out ahead of time; hopefully you will have time to practice and decide which method works best for you for when it comes time to piece the HSTs for your Chasing Chevrons quilt.
Please note, the measurements for these methods and blocks are not the same as the quilt along so don't go getting crazy and start cutting your fabric for the actual quilt. I'm showing the math for figuring HSTs for others who might use this tutorial and well, because I'm nice. But this is just practice for the real quilt...
Method 1 {my favorite}
Want to make 4 HSTs at once? Then this is the method for you. Now, I know there is a bit of controversy over creating blocks with bias edges and this method does that. However, I would almost rather create a bias edge and use some starch than sew actual triangles together on the bias.
I have made several quilts, including my Blissful Zig Zags using this method and I have never had an issue with the bias edges. I certainly would not post a suggested method if I had not tried it myself and had plenty of success. :)
There is some math involved in this method but an easy way to figure what size your HSTs will be it is:
Beginning square size x 0.64 = HST size
If you know what size your HST should be then use this to find what size the beginning square needs to be:
HSTsize/0.64 = beginning square size
To make 4, 3" HSTs, grab two 5" squares. Ideally, you want one light square and one darker square to create good contrast.
Place the squares right sides together {RST}. Stitch a scant 1/4" all away around the perimeter of the block. Pivot at each corner until you reach the beginning of your stitching.
What's that you say?? Yes, I know the squares are completely sewn together. Don't worry... ;)
Take your squares on your cutting mat. With a ruler and a rotary cutter, cut diagonally from corner to corner.
Keep the halves together and cut diagonally from corner to corner again.
Open your 4 quarters to reveal 4 HSTs! Here's where it gets important: Lightly Press {don't iron} the square open. Using a back and forth ironing motion will distort those edges!
We will talk more about the often debated directions in pressing seams when we get to that step in the quilt along. It will be so much fun!
Now grab some starch and lightly mist your open block. If you have never pieced with starched blocks then be ready to be amazed! Again, press the block to set the starch. You can use spray starch in a can if you'd like but I like making my own from this great recipe over at Pins & Bobbins.
Once you are done pressing, you will have 4 finished HSTs ready to be trimmed to size. If you are accurate in your piecing, you will basically be trimming the dog ears on the corners and that's about it.
Method 2:
This is my second favorite method. To determine how big your starting squares need to be, add 7/8" the size you want your finished HST to be.
This method will let you make 2 HSTs at once. Not bad!
Take 2 squares and place them RST.
With a ruler and a marking pen or pencil, draw a diagonal line from corner to corner.
Pin your squares together and stitch with a scant 1/4" on both sides of the line you drew.
Once done, take your ruler and rotary cutter and cut along that same line. Follow the same pressing instructions from above, trim the HSTs and you're done!
Method 3 {my least favorite method}:
This method seems to invite the most opportunities for error. Of course this is only my opinion; your experience might be different. It also only produces one HST at a time. Boooo!
There's still a little math involved in this method. If you are cutting your triangles out of squares all you need to do is add 7/8" to the desired finished size of your HST. For example, if you want a 3" finished HST, then you would cut the square to measure 3 7/8".
Once you have your square, I highly recommend lightly spraying it with starch and pressing the square to set the starch. This will make your edges a little easier to deal with.
Next, cut diagonally from one corner to the other to create your two triangles.
Place them RST and stitch together with a scant 1/4" seam allowance. Follow the pressing instructions from the other methods. Trim and you now have one HST complete.
Like I said, this is my least favorite method but I know that some people have an AccuQuilt cutter or triangles that they would like to use up. If you choose this method... starch and patience are a must because the edges can get funky in a hurry.
So there you have it! Make one at a time, two at a time or, four at a time... hmmm.
And lastly, what's a scant 1/4" seam allowance? Something I didn't bother with until I started making HSTs and couldn't get my sizes to come out right. Turns out it's pretty important sometimes! A scant is literally a few threads short of a true 1/4". Turns out that a few or so threads can add up after opening a block and pressing because of the fold and how our machines stitch with locking threads.
The best way to set your machine to sew a scant 1/4" is a little trial and error. Take a 5" square and cut it exactly in half. Each piece is now 2.5" wide.
If you have a 1/4" presser foot, start there. Stitch a seam, open, press, and then measure the finished block.
You have your scant seam allowance correct when your open and pressed piece measures exactly 4.5" wide. If the measurement is perfect then you've got it!
If your block is a tad too small, just adjust your needle position to make your seam a little less than a 1/4". Stitch another seam and measure again. Lather, rinse & repeat. It might take a few tries but it's well worth it to have your HSTs turn out correctly!
As always, if you have any questions please let me know.. :) Linking up for Fabric Tuesday too!