The HST or Half-Square Triangle is one of the most popular blocks used in quilts. It can work as a block itself or as a building unit, part of a bigger block design. Take a look at this quilt I made using only HSTs for a beginners class.
The Half-Square Triangle is made out of two square pieces stitch together and cut in half (I will explain the process later on). You will find many tutorials online about how to get 4, 8 or more HSTs out of two squares of fabric but in this post, aimed at beginners, I am going to focus on how to get two :) I will also explain how to maximise your sewing time by using the chain-stitching technique.
HSTs two-at-time for beginners
The math behind the technique
To get a specific finished measurement on your Half-Square Triangle, you need to start with a bigger measurement for your original squares. What I do is I add 1" to my desired HST finished size.
So for example if I want my two finished HSTs to be 4'', I need to start with a pair of 5'' squares. Usually, you will need to trim the HSTs down before joining them to the other blocks or units on the quilt as you won't get a 4'' HST straight after joining the 5'' squares; you will get a HST that is bigger.
With the 5'' measurement, you are giving yourself space for error, apart from the added seam allowance.
Steps to get two Half-Square Triangles
For this part, I am using the Kaleidoscope Quilt as an example.
1. I start by picking up one 4 ½'' x 4 ½'' lilac colour square and one 4 ½'' x 4 ½'' background square and draw a line with a fabric pen or chalk to the back of one of them, from corner to corner. (I need for my finished, before sewing, HSTs to measure 3 ½'').
2. With right sides together, I sew a parallel line to the right of the drawn line with a ¼'' SA. I then repeat at the other side of the marked line.
3. Then, I cut the square along the marked line using my rotary cutter and quilt ruler and press the seams of both resulting HSTs open or towards the darker colour. I then cut the 'dog ears' and square-up the units so that both measure 3 ½'' x 3 ½''.
The so called 'dog-ears' are those cute little extra pieces of fabric in the shape of a triangle that result from sewing the two main squares together. It may sound silly, but I actually collect them and keep them on a jar in my studio :) It makes me happy just looking at it!
Chain-stitching technique for time-saving
Now that you know how to make a Half-Square Triangle, you can learn the chain-stitching technique to save time by stitching many at the same time, one after the other. This technique can actually be used for anything sewing related but it is used a lot when creating blocks for a quilt.
The premise is basically not having to start and finish your line of stitches with each block or unit but continuing sewing and creating a chain of thread in between blocks or units. Follow the steps below to know how it works.
1. First, I usually place a 'header' (a small piece of fabric folded a few times) as a starter to make sure that the possible bird nest of threads stays there and not on my block and sew across it.
2. Then, I place my first block or unit right after the header and start sewing using the seam allowance I need to follow.
3. Before finishing that seam, I place the next block or unit I need to sew, right after the first block, leaving just a chain of about 1cm or ½'' in between.
4. And keep adding all the blocks or units I need to sew one by one.
5. When I finish, I will end up with a sort of garland of blocks joined by short chains of thread. Now, I just need to cut along the threads. This way I save time and only have to start and finish once instead of doing it for every single block.
If you like these colours and the design, I have used the Kaleidoscope Quilt pattern as an example.
I hope you found this post interesting :) Thank you for reading and I will see you back here soon.
Happy quilting!
Ana
xxx