Monday, June 11, 2018

Conquering the HRT - half rectangle triangle



At a quick glance, constructing a half-rectangle triangle (HRT) might not seem much different than constructing a half-square triangle (HST).  The end objective is the same for the finished block - seam lines intersecting each corner.  But construction and trimming are a bit different.
HRTs can also face two different directions - the seam can run from the upper left to the bottom right (like the red HRT in the illustration) or the seam can run from the bottom left to the upper right (the yellow one).   As you cut your fabric, cut right side facing up whenever possible -  it avoids getting your brain all twisted up!

This HRT tutorial will focus on creating a HRT with a finished size of 2 x 4 '' , oriented like the red HRT in the illustration. 

There are 3 basics approaches to creating a HRT:

  1. Cut and trim the final block to the size you want. (My personal favorite)
  2. Cut precise pieces and no trimming required.
  3. Paper piecing (best choice for precision)

Let's get started!

Option 1: Cut and trim the final block.

To begin, cut two (2) rectangles each 3 x 5''.    Want a different sized HRT?  Start with the desired finished dimensions - add 1'' to the width and 1'' to the height to calculate cutting size. 

Place fabric RIGHT sides up, put a small mark 1/2 '' in the upper left corner and in the bottom right corner.  (Shown in photo A by the pen and the ruler.)  I cut my fabric in pairs, drew the marks on the top fabric and then stacked (right sides facing up) and cut.  Want your HRT to face the other way?  Place fabric RIGHT sides up, put a small mark 1/2 '' in the upper right corner  and in the bottom left corner. 

Align ruler against the dots and carefully cut. (photo C)  The cutting line is illustrated in photo B.


Place both parts of the HRT next to each other (photo D).  Flip one and place them right sides together (photo E).  The top fabric will overhang a small amount at the top and the bottom fabric be visible on the bottom.   Sew together with a 1/4'' seam.  Be careful not to stretch since these are bias seams.  (photo F)  Press.


At this point, your HRT will be roughly 2 1/2 '' wide and about 5'' tall.

If you are lucky enough to have a specialty ruler just for HRTs, you can start trimming your blocks to the correct size.  But if you don't keep reading!

Before we trim, let's go back and look at the angle of the seam line.   We want our seam line to intersect the corner in our finished block but this means it will NOT intersect the corner in our unfinished block - the block size we are going to trim to.  (Scroll back to that first illustration with the green HST and the red HRT side by side - can you see the difference in the angle?)

Let's look at this up close.  (The solid line is the finished size and the dotted line is unfinished.)

Since the seam line doesn't intersect the exact corner of the unfinished size, you need to be careful how you place your ruler.

Our unit currently measures 2 1/2 x 5'' and we want to trim it to be 2 1/2 x 4 1/2 ''.  Roughly this means a possible sliver trim on each side and 1/4'' from both the top and the bottom.

Position the ruler so a 1/4'' from top and left side of the ruler hits the seam line.  If all is perfect*, the seam line should also intersect the ruler at 2 1/4'' from the side and 4 1/4'' from the top.  (Tip - I put a piece of washi-tape near that point to help me find this point consistently.)  Trim and then flip around to trim so the HRT measures at 2 1/2 x 4 1/2"

* Things will never be perfect.  The block will likely not align perfectly. When this happens, I did my best to align things as evening as possible.  For my** quilt, things don't have to be perfect.  If I wanted perfect, I'd paper-piece these!

** It is your quilt.  You get to decide how perfect you want things to be.



You can also make two at once - similar to HST - but this involved making dots on both pieces of fabrics and lining those dots up with pins.  I tried it a few times and decided it was too much work.

This method yields two IDENTICAL HRTs.


To make two at a time, place your two pieces of fabric side by side.  One should be right side up and one should be wrong side up.  On the right side up fabric (the gingham print below), place your marks 1/2'' from the top and bottom corners.  For this tutorial, I placed my dots in the upper right and bottom left.   On the wrong side up fabric, place the dots in the opposite corners.  (photo A)

Place right side together, using pins to align the dots.  (Photo B) Sew 1/4'' on either side of the line. (photo C).  Cut apart between seam lines and you will have two identical HRT (above photo.)

I found this method to be too time consuming - lining up the dots to pin was too fiddly for me and was just an extra step.  It did not produce more accurate results.


Option 2: Cut precise pieces and no trimming required

There are a number of specialty rulers on the market that can help you create just about any block you want.  The HRT is no exception - the Tri Recs ruler can help you achieve that perfect HRTs every time!

To get started, you'll need a strip of fabric that maps to the unfinished dimension.  For this example, we need a 4 1/2'' fabric strip.

Fabric right sides up, align ruler along left edge and carefully cut along the diagonal.   Rotate the ruler 180 degrees and align along diagonal edge.  Cut along straight edge.  This ruler has a little corner cut out in the upper left.  It is important to cut that as well.

Once your pieces are cut, place both parts right sides together.  This cut corner allows you to align your pieces without any guess work.  Sew along the diagonal seam and press.   If any trimming is needed it will be very minor.


This is a great construction method if you don't mind spending time on prep work.  It is ideal for yardage and generates zero waste!

Option 3: Paper Piecing


The advantages to paper piecing HRTs - or any block - is accuracy.  It can generate more fabric waste than other methods but nothing beats paper piecing to get nice looking HRTs!


Want to give it a try?  Check out my paper piecing tutorial and download a paper piece HRT sheet.


Hopefully one of these techniques will map to your interests.  Since I am primarily dealing with charm squares, I'm going with the first method.

I'm making lots and lots of HRTs for my quilt and while many of them are turning out close to perfect, a bunch of them are not.  I've decided to embrace the wonkiness of this block.  If the seam isn't perfectly aligned, I am not redoing the block - I'm leaving it in.

Are you ready to tackle a HRT?

I'll be linking my tutorial at Tips and Tutorials at Quilting JetGirl and Meadow Mist Designs.

Have a wonderful day! Patty

13 comments:

  1. Interesting. I prefer a precise template set and haven't a clue what prep work before hand you refer to. It's less time consuming then marking your corners 1/2" in first and then squaring up afterward and no less accurate besides. Well. For me. And I won't paper piece.

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    1. We’re all different. For some, it’s 'the process' that is the most fun. What’s more work for one Quilter is easy peasy for another. Be nice, now.

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    2. All 3 of these methods for creating HRTs have advantages and disadvantages which is why I covered all of them. (I'd love to know if there are others!) I know I will use each of these at different times to create this fun block.

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  2. Great tips for tackling an HRT, Patty. I definitely want to use them more in my quilts and appreciate the refresher!

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    1. Thanks! I've been wanting to make a quilt with this block for a long time - turns out it is a lot more fun and easy than I anticipated!

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  3. Looks like you have definitely conquered!! I am getting ready to do a similar block- TIS blocks...I am hoping the bloc loc will make them a snap to make :)

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    1. Its fun to make something other than a HST or FG, isn't it! Looking forward to seeing you TIS blocks.

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  4. First thing tomorrow, I’m going to try each method (except the pp) to see what’s easier for me! Except for pp, I’ve never made this unit before because it looked too complicated. Thanks for taking the time to write up this post.

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    1. Let me know which way works best for you!

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  5. These pieces can be truly annoying - the tri recs ruler or the paper piecing. Great tutorial.

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    1. Thanks so much. I'm hoping everyone will find a way to enjoy making these fun blocks.

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  6. This tutorial is awesome. I've wanted to try these guys for a while but I find the instructions daunting. I'll try them out as well and see what works best for me.

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    1. Thanks so much Lisa. I'm having a blast - cut lots of fabric yesterday and time to start sewing more!

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