Tuesday, July 16, 2013

Technique Tuesday - Setting Blocks on the Diagonal

Today we are introducing a new feature on the blog: Technique Tuesday with Debby Kratovil. We are excited to have Debby sharing some of her favorite piecing tips and tricks with our blog readers, and we know you'll find the information she shares incredibly useful. 
Florabunda Collection
I'm delighted to share with my Benartex visitors a quilt technique that has baffled many of us: How to set blocks on point. What are the magic numbers to cut those pesky side and corner triangles so they not only fit, but there are no bias edges along the outside edges? This is one of the most popular lessons I have ever offered. I begin with the Florabunda collection by Broadway Studios. Pretty, huh?

I wanted a green fabric for the basket handle and applique, so I selected a fabric from an older the Benartex collection called Katie. By the way, I used that Katie collection to make the quilt on the cover of my new book and I called it Katie's Garden. That was easy!

Cover quilt using that awesome Katie Collection
I selected a block from my 2013 desktop quilting calendar
My block inspiration from my 2013 Block a Day calendar
Auditioning fabric for the side and corner triangles
I selected two of the fabrics and auditioned each one against the block. I like the second one better.
I like this better - stronger contrast
 Time to take the plunge and CUT!
Cutting the SIDE triangles from a 15-1/2" square
There are two sizes of triangles to consider. The first one is the side setting triangle (in picture above). We cut a square that is the finished size of the block (10"), MULTIPLIED by 1.414 and then we add 1-1/4" to that number for seams. I have a handy chart at the end of this blog post, so hold on and stop rolling your eyes. This is math talk, not trash talk! Our number is a whopping 15-1/2" square. Each square gives me 4 side triangles (that's all I need for my 4 block quilt).
Cutting the four CORNER triangles from two 8" squares
The formula for cutting the triangles for the four corners of the quilt: finished size (10"), DIVIDED by 1.414, then add 7/8" for seams. Now I'll show you how they look.
Two side triangles sewn on opposite sides of block; Corner triangle at the ready
The blocks are joined into DIAGONAL rows. The side triangles (there are 4) are added to the top left block, and then the single corner triangle. Press seams toward the floral triangles.

When you lay out your pieces as shown in the diagram below, it's easier to see the sewing sequence.

Can you see those last two remaining seams left for me to do?
Three diagonal rows; 2 remaining seams to do
I will sew those last two seams and then press them open to reduce bulk. When you consider setting your blocks on point, it opens up some wonderful setting options.

I will answer a quick question you might have about the seam allowances I quoted above. When a square is cut into FOUR TRIANGLES, you always consider the block size it will work with. And, you always add 1-1/4" to the size of the cut square so that it will fit the block or unit it is to go with. When a square is cut into TWO TRIANGLES, you consider the block size and only add 7/8" for seam allowances so it will fit with the block or unit it is paired with.

Here is my handy, dandy chart with formulas for standard sized blocks.
And I've done the math for most of them; just find the block size!

You can download this chart and print it out; then hang it up in your sewing room!
Setting Blocks on the Diagonal by Debby Kratovil
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  1. Thanks Debby!
    I've printed off the chart and pinned it on my sewing room wall!

  2. debby makes even the hardest quilt blocks seem so easy! sometimes, it makes me want to slap myself in the head and say duh!!!! lol barbara babscorbitt@gmail.com

  3. Thank you for the chart, Debby. Technical Tuesday is going to be a event!

  4. This I can use; thanks so much. I also love that basket block; the embellishment makes it unique.

  5. Thanks Debby I really needed this, I have a bunch of quilt blocks that I have wanted to set on point but not sure how and now you have made it easier and I will give it a try..appreciate it...

  6. Your timing is impeccable, Debby! I'm getting ready to do this very thing and have been wracking my brain trying to remember where I put the instructions for figuring those triangles. Now I can get right to work this morning, and I don't have to dig through all of my binders!! Thanks so much. (I'm going to make several copies of your formula chart and put one in the front of EACH binder!!)~karen

  7. Perfect timing! I just pulled out a UFO and am adding the sashing now and then was going to try and figure out how on earth to cut those edge triangles to set the diagonal rows. yay! Now the work is done for me and I can just cut & sew - thank you!!

  8. Back with a question --- what about when blocks are sashed? I did a quick google search which says add 1 unit of the sashing measure (so an 8" block, finished, with 2" (finished) sashing becomes a 10" block and then use the same formula/method) -- is this correct?

    thanks for any feedback! :)

    1. Hi. I will have the Benartex blog moderator also send you an email so you are sure to get this response. Yes, if you've sashed the block and it's now a 10" Unit (8" block size PLUS the added strips), what you need to set on point is a 10" square. You work with that number for getting the correct triangles for sides and corners. Good question!

  9. Love that fabric collection and your post has me thinking about yet another basket quilt. I love baskets! Thanks!

  10. Your tips have been very helpul and I downloaded the chart for referencce - thank you!!