How to Trim Half-Square Triangles in Three Easy Steps!

Except for the middle square, this block is made up entirely of half-square triangles.

Hello! It is wonderful to have you stop by again!  I hope your week has been happy and productive so far. I know from experience that some weeks just don't go as planned. Sometimes we lack opportunities to work on our hobbies and projects because pressing needs in our home and family come first (which is the way it should be). 

​Sometimes it's just survival!  This week has been a little of both for me. At times it has been extremely hectic, but I have managed to make time for quilting projects and client orders. All in all, keeping balance has been possible and I am very thankful for that.

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When I first learned to quilt, I thought all you needed to do was sew blocks together in rows.  However, as I made progress from simple squares to blocks that were constructed of more than one piece, I started having trouble getting my rows to line up together because my blocks were lop-sided.  I was frustrated, but I was far away from giving up (Mom always said that I was "bound and determined"...). After doing some research I found that the problem was the fact that my blocks weren't nice and square.  After I learned to "square up" my blocks, sewing my quilts became easy as pie...well, almost.

So today I wanted to discuss the important topic of "squaring-up"  our  half-square triangles (or HST's)... it can be done in three easy steps! Just a side note here:  if you are reading my blog for the first time, you may want to read How to Choose Quilting Tools for Successful Cutting and Measuring  for some helpful information and links on the tools in this discussion.

The truth is that no matter how carefully you cut & sew your quilt pieces, sometimes the blocks will be uneven and will need to be "squared up"  in order for seams to match accurately within your quilt.  Even though it takes a little more time, the end result is worth every minute because the final result will be an accurately pieced quilt (and a lot less frustration). Below is a quick and easy tutorial I've written especially for you on how I trim my half-square triangles.

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Supplies:

• Square ruler ( I like a 6 1/2" because it works with most of my blocks, but you can use one that is smaller or larger)
• Rotary cutter ( I normally use a 28mm blade when using a square ruler because I find it easier to handle when trimming  smaller edges.)
• Self-healing cutting mat ( I like to flip mine over and use the back because I do a lot of trimming and don't want to wear out the front of the mat.)

61/2" Square Ruler and 28mm Rotary Cutter

Since I've been working on a new doll quilt pattern that is mostly made up of HST's, it seemed like a great example to use for this tutorial.

Once you've decided on what size your blocks need to be, you are ready to do the next three steps. Mine will be 2" square finished size after trimming.

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Step 1:

Start with the colored (or patterned) side pointing down to the bottom right (see image above). Lay the diagonal 45 degree line of the ruler exactly on the diagonal seam of the block as above. Depending on how much needs to be trimmed, there will usually be some extra fabric that extends beyond the outside of the ruler. Be careful not to have the other two sides of your block on the inside of the lines (or 2" as in the example),  because when you do Step 2, the block will be too small.

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Step 2:

Beginning with the right side, carefully trim the block while holding the ruler firmly in place to prevent slipping.  Next, trim the top.The first two parts of your square are now trimmed as shown above. Great job!

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Step 3:

Now simply flip your block so that the colored half is on the top left and trim the remaining two sides. Be sure to keep the diagonal of the block lined up with the diagonal of the ruler. All done! See, that was as easy as pie!

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From the picture above it is easy to see how squaring up our blocks will make a huge difference in how the entire quilt turns out.  Not to mention, we will have so much less frustration in matching up blocks and seams!

You are doing great and I'm so proud of your efforts! I'm here for you if you have any questions, and I'll always do my best to help and encourage you. Now,let's go tackle the rest of those HST's and get our quilts finished.