Montreal Modern Quilt Guild: Skillbuilder 2017-18

I love HRTs (half-rectangle triangles). I guess that is why I was asked to do a demo for our skill builder project. I have used HRTs in few projects my-self. Here are few pictures.

Facets quilt by Josée Carrier

HRT table runner by Josée Carrier

HRTs offer the same endless layout possibilities as HSTs (half-square triangles). But, the difference in width and height adds another dimension to projects. Further more, you can create curve effects by playing with the proportions of your units. This can really add movement to your designs.

Techniques for HRT units

While working on my projects and preparing for this demo, I have explored different techniques for making HRTs.

The difference with HSTs is the angle at which you need to assemble the two right-angled triangles to form a rectangle. Since it's not a 45° angle, it makes alignement of the two pieces more challenging. You can't just put two pieces of fabric right side together (with edges aligned) and sew on each side of the diagonal to obtain two units. You need to figure out at which angle to align and sew the pieces of fabric.

The other difficulty with HRTs is that you need to plan the orientation of your unit. With HSTs, you just need to rotate your finished unit by 90° to change the orientation of the diagonal. You can't just flip a HRTs because of the difference of width and height. You need to plan ahead if your design requires a diagonal from upper left corner to lower right corner or a diagonal from upper right corner to lower left corner.

Here is a summary of techniques with some links to great references.

Paper piecing

Paper piecing is one solution. It is the most precise technique. However, it's probably not the fastest one. And you'll probably end-up with more fabric lost. If you do love paper piecing, here is a great tutorial by Wayne Kollinger for making HRTs.

Cutting with rulers

You can also use rulers to cut your triangles at the right angle. There are a variety of rulers available. Here are a few: Split Rects ruler, Recs tool and Perfect Rectangle ruler. All rulers I have seen allows to create HRTs for which the height of the finished unit is twice the width (2 to 1 ratio). In most "traditional" blocks, the HRTs have that proportion. Here is a tutorial by Wayne Kollinger and a video by Deb Tucker (Split Rects) explaining how to use them.

Cutting without rulers

Here is another tutorial by Wayne Kollinger explaining how to cut the triangles without the rulers. Again this applies to HRTs with a finished height that is twice its width (2:1 ratio). The main disadvantage with the last two techniques is that you need to sew on bias cut edges.

Alignement using templates

One solution to this is to make your HRTs like HSTs: by sewing on the two sides of a diagonal and by cutting it in half on the diagonal. In that case you end up with two units with the same orientation. To do so, you need to find at which angle to align the two rectangles. In previous projects, I had prepared alignement templates for different sizes of finished HRTs. I had written a tutorial on Sew Mama Sew explaining that technique. The limitation of this technique is that you are limited to sizes (proportions) for which the templates were built for.

Alignement using marks

You can also align the rectangles using a technique proposed by Latifaah Saafir. She marks dots on both pieces at two opposite corners to form a diagonal. She marks her dots at 1/4" from each edges. This works great for finished HRTs with a 3:2 ratio (like HRTs with finished sized 4"x 6"). You can find the tutorial on The Modern Quilt Guild blog and you'll find a demo in an Episode of Fresh Quilting. I have found however that the HRT's finished size is less predictable for other proportions as the rectangle is not sewn at the right angle.

Tutorial

Here is a small variation on the technique shown by Latifah Saafir to make it work with units of different proportions.

Cutting

First, cut your 2 rectangles one inch wider and longer than the HRT's finished size. So for a finished HRT of 4" x 6" (unfinished: 4 1/2" x 6 1/2"), cut your 2 rectangles 5" x 7".

Marking

Mark dots for the diagonal at 1/2" from edges at opposite corners on the wrong side of each rectangle (with the same orientation).

Mark the diagonal by tracing a line passing by both dots on one of the rectangle.

Positioning

To align the rectangles, place them right side together with the one with the diagonal on top. Use a needle to pass though the dots of a marked corner on both pieces.

Repeat for the second corner.

Sewing and cutting

Sew on each side of the diagonal at 1/4" from the line. Then cut on the diagonal.

Trimming

Open-up your unit and press. Then proceed with trimming, which is the key to good points. The HRT's unfinished size (or cutting size) is 1/2 inch wider and longer than the HRT's finished size. So, for a finished HRT of 4" x 6", you need to trim it to 4 1/2" x 6 1/2".

For trimming, I find helpful to mark circles on the ruler to see the end-points of the diagonal on the finished HRT. For a HRT with a diagonal from upper right corner to lower left corner, I'll draw a first circle at 1/4" from each edges (to account for seam allowance). And I'll draw a second circle at 4 1/4" from the right edge of the ruler and at 6 1/4" from the top edge of the ruler.

Then position the ruler on your assembled unit to have the diagonal seam running through both circles and trim a first corner.

Then turn around and trim the second corner in the same manner. Just a note, the longer and narrower HRTs offer less room to trim in width.

That is it! With this technique, you end up with two units in the same direction. I invite you to try the different techniques and find the one what works best for you and the project you'll be working on.

Inspiration

Now I leave you with some inspiration for your future projects. Here is a Pinterest board I created with ideas on how to use HRTs in your quilts and other great resources. My favorite quilts using HRTs to date are the following: