From Squares to triangles (HST)

In this lesson, we are going to deal with blocks with triangles and the way we put them together. Half Square Triangles is the name we call them (HST)
Making triangles out of squares is so easy and can be made in such a clever way, that I could not think of, before starting the patchwork. How we make them: we take two squares of the same size and we pin them right sides together. We draw a line on the diagonal line.
We also draw a line on the right side of the diagonal, indicating the seam allowance (0,75 cm or ¼”). We repeat this on the left side. We sew on those lines on the left and the right of the diagonal. Take a look at the photo on the right (0,75cm seam allowance).
If you already know where the seam allowance is on your machine feet, then you may sew, having just the diagonal. But be careful. This block needs to be sewn with great accuracy.
We cut on the diagonal using the scissors or the cutter and voila:
Our former bigger squares were transformed to smaller ones that are formed by two triangles. Several people iron at this stage. I avoid it, because they tend to loose their shape. I finger press the seams and trim the corners.
We join in pair, as shown on previous lessons and then we join the pairs, taking care of the seams on the back side, so that they are not at the same side (see right picture).
The result of this placement is very common and the final 4-patch block is called pinwheel.
Please take a look at what happens when we did not pay attention when sewing the pairs.
What we can do in this case? We take the seam ripper, rip the seam and sew again.
Let’s take a look at what we can do with those HST apart of the pinwheels. I found this image on the blog, that is very helpful and indicates the so many ways to put those HSTs together:
You can see how many possibilities there are with HST’s and imagine how many secondary patterns we can have. If you add some color on top of that, you may understand why I adore patchwork. Two persons can start with the same fabrics and the same technique (eg HST), the final result will vary for sure, if they put it in different way.
Let’s name some of them (photos are from
Friendship star       
Flock of geese       

 Double pinwheel

Eccentric star                         
Grape basket

Birthday cake 

King’s crown


I hope this lesson made you understand the magie of patchwork!!!!


  1. Να το τολμήσεις σίγουρα και μετά να κάνεις και διάφορους συνδυασμούς. Έτσι θα κολλήσεις σίγουρα το μικρόβιο, γιατί αυτό το σχέδιο είναι από τα πιο ευέλικτα


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