Tutorial // How To Trim Half Rectangle Triangles
Over the next few weeks, I’m going to share helpful tips, tricks, and tutorials for making Half Rectangle Triangles.
Original Half Rectangle Triangles: Tips, Tricks + Tutorials Post
Half Rectangle Triangles: Does the Angle Make a Difference?
Paper Piecing Half Rectangle Triangles
Favorite HRT Ruler: The Bloc-Loc Ruler in Large –it’s pricey [you get 2 rulers] and makes trimming HRTs a dream
This tutorial is all about trimming HRTs--there are a number of ways that people make and trim Half Rectangle Triangles, some include offset sewing in the first place, some include increasing the seam allowance--this is the only way that I consistently got the same, accurate result. Happy Trimming!Once you have your Half Rectangle Triangle unit (more information forthcoming in the Half Rectangle Triangle Quilt Tutorial), how do you trim them!?
Trimming HRTs
1. Select (1) HRT sewn unit [start with a unit that was cut in half diagonally from top right corner to bottom left.]
2. Line up your ruler so that the 1/4’’ x 1/4’’ intersection resides in the seam line.On some rulers, there is a dot or a crosshatch to make this easier.
3. Trim the long edge first--make sure not to angle the HRT unit, but keep it straight (right angles aligned to the ruler marks on your mat). Then trim the top.
Note: Notice that you do not trim from corner to corner, as you would when making a half square triangle.
4. Rotate the HRT unit as shown in the second diagram.Determine how large you need to trim the HRT units. You can refer to the Half Rectangle Triangle Cutting Chart if needed. This unit is trimmed to 3-1/2’’ x 6-1/2’’.
5. Line up your ruler in preparation for trimming to the correct size as shown; in this example, this is a large HRT unit, so trim to 3-1/2’’ x 6-1/2’’. Ensure that the 1/4’’ x 1/4’’ intersection lies in the seam line as before, and trim to size. Notice that the trimmed units are not trimmed from corner to corner, but are offset.
6. The same method is used to trim HRT units cut in half diagonally from top left corner to bottom right.
A Note on Trimming HRTs
You might be tempted to trim your HRT units from corner to corner, as you would a Half Square Triangle unit. Resist the temptation!
If you trim HRT units from corner to corner, instead of offset trimming (as explained on page 5), your seam allowances will be off. In order to keep your points, you will have to increase your seam allowance to somewhere between 3/8’’ to 1/2’’ when you sew vertical rows of HRT units (at least 1:2 ratio HRT units) together.
