I’ve received a private commission for a special project, which has resulted in me making dozens of half-triangle squares (HTS’s) or Half-Square-Triangles (HST’s) — Quilting uses one of those names for these things, and I forget which.
The essence of the process is that you first cut squares of your chosen colors. It’s important to get the squares exactly matched. Iron and press them. Then you put them, right-sides together. Iron and press them. Then sew a square seam around the squares 1/4″ in from the edge. You then have a closed pocket, which you cut from corner to corner in both directions.
The seams that used to be on the edges of the square, are now running down the middle between two triangular pieces, and you have a square made up of two right triangles that match on the hypotenuse (see — you do need geometry!)
I’ve now produced … let’s see. I have forty piles of four HSTs each (I think it’s HST. Is it, readers?) for 160 squares. And these 160 squares are going to be sewn into forty larger squares, each of which is going to be a pinwheel or other pattern you can produce with HSTs.
There’s a broad range of HST patterns possible, too, with just four squares. The most commonly known one is the pinwheel, which simply alternates squares.
As it so happened, the piles of still-folded triangles in dark blue and dark red formed a pinwheel as I cut them and stacked them into sets. You can see the opened and ironed HSTs in piles on the left-hand side of this second photo; and each quartet of colored squares divided into triangles along the diagonal becomes one square in the side of a quilted bag.
What do they look like all together? Something like this mess. Eventually, all of these will be assembled into squares. And the squares will be assembled into…
Well. Private commission, you see. Some parts of this may just never go public. That’s the nature of private workings, sometimes: the magic belongs to the one who commissions the work, and to them alone.
All the same, you can get a sense of what’s possible from this grid that I made for myself. If you have four patches of any pair of colors — dark and light, contrasting, two hues of the same color, white and black or whatever you want along those lines — it’s possible to produce all of these patterns and more, as well as their reverses/inverses. And these designs have a certain power, a certain punch to them. In a 4×4 grid of HSTs, other things become possible… but you need to produce two of those larger squares sewn together and cut in order to make that four-by-four grid in the first place. Here, there’s a range of options with just one.