This week's homework was using 16 Half Square Triangles to make a block. This is such a clever concept and I think will help with future quilting a great deal. I found a couple of tutorials to explain the principles of this technique, because any description I gave would be rubbish!
How to Calculate Half Square Triangle Measurements
How to Measure and Cut Half Square Triangles
This is a good video on how to measure, cut and sew a single Half Square Triangle.
We were taught how to make a grid of 9 squares using two pieces of contrasting fabric. Each piece of fabric is pressed and laid with right sides facing each other. Then a grid is marked out, with each square measuring 7/8" greater than the size of the required final square. Below is an illlustration of what we were told.
All the red lines marked were 1/4" away from the central diagonal lines, on either side. These lines were sewn. Then all the black lines, including the vertical and horizontal ones, were cut using a rotary cutter.
Then each piece was then pressed with the seam allowance towards the darker side. This gave 18 squares, of which we only needed to use 16. We then laid out our squares in a pattern of our own making. I cheated and used a pattern I had seen in a magazine.
I am half pleased with my piecing in this block. Our tutor told us to piece in strips and then piece the strips together. I don't think this worked, as I followed this method on the right hand two strips. As you can see, the "arrows" don't line up too neatly. On the left hand two strips I pieced each "arrow" together and then attached it to the matching "arrow". I then pieced these blocks of 4 together. These left hand pieces are much neater and I'm really pleased with how aligned they are.
I learned from this exercise that next time I make Half Square Triangles I will allow 1" extra on each square and cut down to the right size after sewing. I will also piece the pattern in a way that makes sense to me, rather than blindly following the instructions, that may not apply in each case.
Other than the slight mis-match of arrow points on the right hand side, I'm really happy with this block. I love the fabrics I used, especially as the red fabric has not had enough chance to shine in the blocks so far.
I will definitely be using this technique again, as it is a really fast way of piecing together a good size block, with very little waste of fabric.