|The sails in this block from my Sailing School pattern are made from HRT units
Here, as promised, is my tutorial about making half-rectangle triangle units (HRT) without specialty rulers. This method does involve a bit of fabric waste as the units are made a little over-sized, then trimmed down. I think the little bit of trimming waste in exchange for ease and accuracy is worth it.
Traditionally, the HRT is twice as tall as it is wide, so those are the dimensions I worked with.
Step 1: Determine the desired finished size of the unit. (Remember that the finished size is the size in the finished project, after the seam allowance is taken up by sewing the unit into the project.)
Step 2: You will need two rectangles of fabric. To determine the width of the cut rectangles:
- For the cut width, add 1 1/4" to the desired finished width.
- The cut height will be double the cut width.
|Step 2: Cut two rectangles
Step 3: Mark a diagonal line on one of the rectangles. Careful! The direction of the line matters.
- For a left-leaning seam on the finished unit (from upper left corner to lower right corner), draw the line from the top right corner to the lower left corner.
- For a right-leaning seam on the finished unit (lower left corner to upper right corner), draw the line from the top left corner to lower right corner.
- to the left (counterclockwise) for a left-leaning finished unit, so that the upper right corner shifts to touch the upper left of the bottom rectangle, and the lower left corner shifts to touch the lower right corner of the bottom rectangle.
- to the right (clockwise) for a right leaning finished unit, so that the upper left corner shifts to touch the upper right of the bottom rectangle, and the lower right corner shifts to touch the lower left corner of the bottom rectangle.
|Step 6: Rotate marked rectangle
|Step 7: Sew then cut into two units
|What you want to avoid
I've found that using a template to guide my trimming gives me the best results.
|Step 10: Cut out template
|Step 12: Position the template
|Step 13: Trim two edges
|Step 14: Position ruler to trim remining sides
|Seam will not go through corner of the ruler