Split Rectangle Quilt Block Units

Another advanced basic unit is the Split Rectangle quilt block unit. Sometimes this unit is called the Half Rectangle Triangle or HRT. You can find examples of this unit in action in the following quilt block designs:

Now, don’t be fooled into thinking these units will work just like half square triangle units. They won’t. They are an entirely different animal. Also, they are an intermediate block and not for the faint of heart! They may take you a bit of practice!

For starters, a half square triangle will always have the same height and width. This is not the case with Split Rectangles. They can come in a variety of height to width ratios, as shown below.

Illustration of assorted sizes of Split Rectangle Quilt Block Units
Note the variety of widths and heights in these split rectangle quilt block units.

One important thing to know when making these units is that the diagonal can either go left to right or right to left. Since the two different directions are mirror images of each other, care must be taken when cutting your fabrics to make sure you haven’t reversed the unit.

Illustration of pair of mirror image split rectangles
Pair of split rectangles. Note that the diagonal line for the set on the left goes from left to right, while the angle on the other pair goes from right to left.

Here’s an example: Suppose I want to make a finished Split Rectangle that measures 3″x 6″.  I would need to cut rectangles that are 3.5″ x 6.5″

Once your can cut your pieces, draw a line along the diagonal on the back side of one piece.

Arrange your pieces, right sides together, but with the diagonal line piece skewed on top, as picture below.

Once your pieces are in position, sew a seam 1/4″ from the drawn line on each side. Once the seams are sewn, cut along the diagonal and press open. Then trim your piece down to the desired size.

A tool that makes easy work of Split Rectangles is the Split Recs Tool by Studio 180 designs. I’ve found this tool gives great results and it really speeds up the cutting process when making these units.

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