So, you found an awesome pattern that uses the 8 at a time half square triangle method and now you need to cut them apart? Since most of my patterns include HSTs, I thought I would share some tips and visuals for getting the cleanest and straightest cuts.
This tutorial includes a video explaining the process and written instructions below.
- A cutting mat that has two 45 degree diagonal lines that cross over each other.
- A cutting ruler that measures the length of your two diagonal lines on your HST.
- A rotary cutter with a sharp blade.
Find a cutting mat that has two 45 degree diagonal lines that cross over each other. Line up the sewn HST blocks by placing each of the four ends of the drawn two diagonal lines on the two diagonal lines on the cutting mat. See image here for reference.
This image shows one of the four corners lined up.
On a standard mat, lining up these four corners puts the intersection of your diagonal lines on a center cut line on the mat. Place your ruler along the center line on the cutting mat. The intersection of your sewn lines should fall along the ruler line. Make this first vertical cut.
Bonus Tip Here: Be VERY gentle when you lift your ruler after this cut. Try to prevent the cut pieces from sliding around. If they do, line them back up before the next cut.
Following the same process, make the horizontal cut next. Again, be careful not to move the cut pieces.
Now, place the ruler along the drawn diagonal line - not the sew lines - the drawn line. Cut along this line, and yep, be careful not to move anything. If you do though, you can just cut the other drawn diagonal lines in the next step one at a time.
Move the ruler to the final diagonal drawn line and place the ruler along this line. Cut.
You did it. You can now pull your folded half square triangle apart. Press them open and trim.
Want to learn more about making Half Square Triangles. Check out this tutorial.