The Half Square Triangle
When I first started quilting, I would
hear people talk about HST's, I had no
idea what they were. When I asked about
them I was told they are half square
triangles ~ but again, I had no idea what
A half square triangle is a unit in a quilt
block that is made up of 2 triangles of
different fabrics. When I come across
patterns that have you make an HST
by cutting triangles and sewing them
together along the wonky, bias seam,
I always stop and convert the pattern to
this method of making HST's. It is much
more precise this way.
Today we will be working with a 3"
finished square, so by adding our
seam allowances our square will
be 3 1/2" unfinished. To make the
HST we will add 3/4" to our
measurement and cut 2 squares at 4 1/4".
On the back of the lighter fabric we
will mark a diagonal line. I do this by
placing a pencil point at the top of the
diamond shape. Then I put my ruler
up alongside the pencil, using my left
hand, I can pivot the ruler until it is in
the proper place to mark the diagonal
line with my right hand.
This is what the drawn line should
look like. Now place the 2 fabrics
right sides together.
Sew 1/4" away from each side of drawn
line. I find if I run the guide on my 1/4"
seam foot along the drawn line it works
Cut apart on drawn line.
Generally you should press the
seam toward the darker fabric.
This is not always true though, we
will go over that when we get to
the "Pressing for Piecing Precision"
tutorial in the future.
Next you will square up in two steps.
Step One is to place the diagonal line
on your ruler along the diagonal seam
on your block and trim about 1/8" from
the top and and right side.
For Step Two, remove the ruler and turn
the square so that the upper right hand
corner that you just trimmed is now in
the lower left hand corner. Place the ruler
back on the square and line up the left
and bottom edges along the 3 1/2"
guidelines on your ruler and trim the
upper and right side edges.
For each unit that you make you
will end up with 2 HST's.
The Half Square Triangle is one
of the major building blocks for
a quilt. Once you master this
technique you are well on your way
to making precise quilts.