Quilt block # 5 of the Scrappy Sampler is all about half square triangles!
~ This block is made up almost entirely of half square triangles.
I’m going to show you two methods to make half square triangles for any quilt project! Both methods keep the bias on the diagonal of the block and NOT the edges of your block ~ which is important for keeping your HST blocks straight and your quilt from ‘warping’.
2 HST METHOD
For this method add 7/8″ to the finished size you want your block to be and use that as the size of the two starting blocks.
Place two squares right sides together. Draw one line from corner to corner. Sew 1/4″ on each side of the drawn line.
Cut on the drawn line.
Open and press for two Half Square Triangles!
8 HST METHOD
This second method will give you 8 half square triangles…
Start with two squares that are 1 3/4″ larger than the finished size times two.
For a 3″ finished HST ~ 3 x 2 = 6 +1.75 = 7.75 or 7 3/4″
Place two squares right sides together. Draw a line from corner to corner on both diagonals. Sew 1/4″ on each side of the two drawn lines.
Cut on both drawn lines AND make a horizontal and vertical cut in center of block.
Open the triangles and carefully press… try not to drag your iron across the blocks so they don’t get distorted.
Here is some math for both options…
|Finished HST block||Unfinished HST block||Starting block size
2 HST Method
|Starting block size
8 HST Method
|1″||1 1/2″||1 7/8″||3 3/4″|
|1 1/2″||2″||2 3/8″||4 3/4″|
|2″||2 1/2″||2 7/8″||5 3/4″|
|2 1/2″||3″||3 3/8″||6 3/4″|
|3″||3 1/2″||3 7/8″||7 3/4″|
|3 1/2″||4″||4 3/8″||8 3/4″|
|4″||4 1/2″||4 7/8″||9 3/4″|
|4 1/2″||5″||5 3/8″||10 3/4″|
|5″||5 1/2″||5 7/8″||11 3/4″|
For my Tranquil Tree block I pressed the seams open so I wouldn’t have too much bulk at the seams…
Even if your careful pressing it’s a good idea to square it… the extra step will help you avoid headaches later :)
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