Thursday, April 3, 2014

How To: Half Square Triangles

Once upon a time I made an Ocean Waves quilt.  You know the one, made up almost entirely of half square triangles.  At the time I was new to quilting and I dutifully cut out thousands of triangles and pieced them together, bias edges and all.  I did know about chain piecing at the time, so that helped a bit, but the mile long chain was unruly to say the least.

But a few years have passed, and I may be a bit older, but I'm also a lot wiser, and I have a new way of making half square triangles that I love!  And since I've been churning them out this week for a project I'm working on, I thought it might be a good time to share my favorite method for making HSTs.  (note the use of quilter's jargon.  Cool, aren't I?!)

And away we go...

You'll need two 6" squares of fabric.  Lay the squares one on top of the other with right sides together.

Using a quilting ruler, lightly mark a diagonal line a scant 1/4" on either side of both actual diagonals.  Keep reading to see a photo of the marked lines.

In order to the get the scant 1/4", I like to line the corners up in between the 1/4" and 3/16" lines on my ruler.

The marked lines should look like this:

Now sew along each marked line.

After pressing the seams, use a quilting ruler and rotary cutter to cut horizontally through the middle of the unit.  Each resulting unit should measure 3" x 6".

Now cut each unit in half vertically.  

The resulting units should each measure 3" x 3".  Almost there!

Press each unit open.  I usually like to press towards the dark fabric unless it interferes with block construction.

Now align the 45° line on a square quilting ruler with the diagonal of your HST.  Trim along the right and top sides of your ruler, then turn the block 180° and do it again.  This is the worst part of the process, especially if you're making a lot of HSTs.  It may require a good background movie and possibly a glass of wine.  BUT, it's worth the time because the HSTs end up perfectly sized which really helps your blocks to come together nicely.

The final HSTs should measure 2 1/2" x 2 1/2".  Repeat with the remaining seven HSTs.  Two 6" squares yield 8 HSTs that finish at 2" x 2" in a quilt block.

 If you only need four HSTs, start with two 3" x 6" rectangles, draw your lines as follows, and follow the same process.

For two HSTs, start with 3" x 3" squares, draw your lines as follows, and, well, you know the drill!

In case you're wondering:

two 5" squares yield eight 1 1/2" finished HSTs 
two 6 1/2" squares yield eight 2 1/4" finished HSTs 
two 7" squares yield eight 2 1/2" finished HSTs

Happy Quilting!

1 comment:

LEISA DALY said...

Okay. This is amazing! In fact everything to do with proper quilting is amazing to me and seems like MAGIC. The magic of course is Math, which for me, might as well be the same thing! But thoroughly impressed and beautifully explained and photographed! Love it.