Saturday, January 28, 2012

Sew Half-Rectangle Triangles

Method 2

There is no one right way to do things. Each of us has different abilities and sensibilities. What works for one person doesn't for another.

When I teach quilting I've learned never to say, "This is how it should be done." I've learned to say, "This is how it can be done."

In my last post I showed you one way to sew half-rectangle triangles. Today I'll show you another.

This method uses a Recs tool designed by Darlene Zimmerman & Joy Hoffman. It is available from EZ Quilting. This tool is used for making half-rectangle triangles that are twice as long as they are wide.

For demonstration purposes I am assuming half-rectangle triangles with a finished size of 2"x4"

To make 4" long triangles start with a strip of fabric 4 1/2" wide. The extra 1/2" is for seam allowances.

Align the 4 1/2" line on the tool with the bottom of the strip.

Cut along the edge of the tool to create a 2 1/2"x 4 1/2" triangle.

The top left hand corner of the tool is at an angle. Cutting off this small bit of fabric will allow for more accurate alignment when assembling the pieces.

Mirror image triangles are made by flipping either the tool or the fabric.

For the block at the beginning of this post you will need a green triangle and a mirror-image green triangle, a white triangle and a mirror-image white triangle.

When two triangles are placed right sides together the small cut in the corner makes it possible to align them exactly.

In the examples on the right the point at the top of the white fabric marks the 1/4" seam allowance and you can start sewing there.

After the unit is opened and pressed, you will need to trim the little bits at either end.

The block shown at the start of this post is made using 2 half-rectangle triangles 2" x4", finished size, and 2 half-square triangles - one 2"x 2" and one 4"x 4", finished size.

It's a simple block but it can make some interesting designs.

In my next post I'll show you a third way to make half-rectangle triangles.


  1. Oh, for heaven's sake, I have one of those rulers and never thought about using it. I'm off to give it a try. I remember when i bought that ruler several years ago and when I did use it I loved it. thanks for the tutorial!

  2. Caroll

    My wife Linda tells me the recs tool is her favorite way to make half-rectangle triangles.

    I didn't know it existed until she told me.

  3. Dear Mr. Kollinger...I am SO SO SO SO excited I happened upon your blog. I am new to quilting and struggling! I just tried all three of your hrt tutorials, and liked this one the best. I am trying to make this block:,or.r_qf.&bvm=bv.47244034,d.aWc&biw=1599&bih=827&um=1&ie=UTF-8&hl=en&tbm=isch&source=og&sa=N&tab=wi&ei=IUCpUafcOImEygHpqoCoBA#facrc=_&
    Therefore, I am using 4 hsr put together to make a "diamond" shape. I have a question and really hope you can help! There is plenty of room above and below the diamond, but there is no room whatsoever on the sides to allow for seams. How can I fix this problem/add a little wiggle room for seam allowance?
    Also, do you have any suggestions on how I should measure this block out if I am trying to achieve a final size of 12.5"?

  4. dear mr. kollinger,
    i'm so so so happy that i happened upon your blog! i am new to quilting and struggling. i tried all three of your hrt tutorials, and liked this one best. i am trying to combine 4 of these, to make a "diamond" shape, because i am trying to make this block:,or.r_qf.&bvm=bv.47244034,d.aWc&biw=1599&bih=827&um=1&ie=UTF-8&hl=en&tbm=isch&source=og&sa=N&tab=wi&ei=IUCpUafcOImEygHpqoCoBA#facrc=_&
    do you have any measurement suggestions for me, if i am trying to end up with a 12.5" block? also, there is a lot of room above and below the diamond, but none whatsoever on the sides. is there anyway to add wiggle room for seam allowances?
    thank you!

  5. Christina

    If you are using a recs tool, your rectangles will have a quarter inch seam allowance on all sides. When you sew the rectangles together to make diamonds they should end up with quarter inch seam allowances as well.

    Google doesn't recognize the code you sent me, so I assume you are trying to make the kite block that you show on your blog. It is a ninepatch block which means it is made from 9 square patches. If the finished size of the block is 12"x12" then each square patch is 4"x4" finished size. The squares are made using two half-rectangle triangles; so each rectangle has a finished size of 2"x4". Add quarter inch seam allowances and you need to make 2 1/2" x 4 1/2" rectangles.

  6. sorry i posted twice, the first one didn't go through so i had to rewrite the whole thing and then the first one did appear. eek! i am using that tool, but i don't think i scooted it far enough over, so i will try that now. thanks! i actually want 12.5" blocks, so does that mean i need each patch to be 4.5", and each hrt to be 2.5" x 5"? sorry for the confusion and asking so many questions but you have been so helpful already! :)

  7. Christina

    The finished size of a block is the size it will be after it is sewn into a quilt. A block that is 12 1/2"x 12 1/2" before being sewn into a quilt, becomes a 12"x12" block when it is part of a quilt.

    Trust me, you do not want a ninepatch block with a finished size of 12 1/2" because the squares would have to have a finished size of 4.16666666". Add seam allowances and the square would have to be 4.66666666" before sewing. Not an easy or a fun thing to do.

  8. disregard my last question...missed the part where you said 4x4 would be the FINISHED size. think i finally can visualize/understand the difference between finished and unfinished now. thanks again and i will try to check back in if i am successful!