Techniques Sampler Blocks 3 and 4 - HST's

HST - Half Square Triangle.  An HST Block is a square block split on the diagonal line, with one fabric on each side.  The HST is used as a building block for many, many, different blocks and designs.

Block 3 is the Pinwheel Block, made from 4 HST's.

Block 4 is  also made from 4 HST's, but in a different arrangement.

The only difference in these blocks is how they are turned and sewn together.  As is true with all patterns, please read through all the directions before you begin.


We will make 8 HST's each squared to 6 1/2 inches.  This includes our seam allowance to make our 12" finished block. Choose 4 of your fabrics and the background. I like to make HST's a little bigger and "square them up".  This helps keep your measurements accurate and your finished quilt flat. Measure and cut 7" squares from each of the 4 fabrics you chose and 4 from your background.  Use method 2 below to construct 8 HST's. Remember to check the measurement on your seam allowance and make any needed adjustments in order to use your best 1/4" seam.   Press them carefully so their bias doesn't stretch, and square them up to 6 1/2" using a ruler with a 45 degree line that you can place on the seam.  Arrange in the desired pattern and sew together.  Your blocks will measure 12 1/2".

                                      I'll put some pictures of the actual blocks here soon.

There are several ways to accomplish an HST.  Your HST can be its own block, or you can combine several HST units to make a larger block.  This is where you let your imagination run wild.  I want to give you some ideas and you can choose to make 2 blocks for your quilt from these, or you can create your very own.

Here are some of the methods that can be used to make HST"s.

1) Cut 2 triangles and sew them together.  Be very careful not to stretch the bias edge when you sew them together. I would suggest using your favorite starch product before you sew.

2) Cut 2 squares, draw a diagonal line, with right sides together (RST) sew on either side,  and cut on the line.  You get two.  This is the technique I normally use.  It's great for chain piecing and the resulting HST is on the straight of grain.  You also have less chance of stretching on the bias line since you sew before you cut.  Still, be careful not to "iron".  Always PRESS.

3) Cut 2 squares and draw 2 diagonal lines, making an X.  Here's the trick for 8 HST's on the straight of grain.  Sew on either side of each line.  That's 4 rows of stitching.  Then cut on your diagonal lines, cut center top to bottom and cut center side to side.

4) Cut 2 squares, sew all the way around, cut both diagonal lines.  You get four. This method is great for making blocks for a final project set "on point".  Since you are cutting both diagonal lines, you end up with your block on the bias.  Again, use your starch and add a stay-stitch along any edge that will be on the perimeter of your quilt.  As your project gets larger, the weight of it will tend to stretch those exposed bias edges.

5) Sew 2 strips together in a tube and cut triangles alternately from each side. This is a great method for making HST's and diamond shapes.  Everything I said about bias in method #3 applies here also.