Tuesday, September 1, 2015

Back To School Blog Hop: So, Does the Diagonal Method For A Pieced Backing Really Work?



In the years I have been quilting, I've  heard about a method to extend the width off-the-bolt quilting cotton and always wondered about it. It was a little like the legend of the summer camp ghost - evanescent.  Ethereal......

What was this all about?  How was it done?  Did it really work?

With a long arm machine in my studio,  having "ready-to-load"  backing is critical.
I've got too many tops that need to be quilted, and not enough time to fuss around with backings.

It should also be said that I *may* occasionally look for a shortcut to reduce my work load.   Not that I'm lazy....but, I have my "priorities" straight.  aka: lazy.

I've looked up the method a dozen times, but it included the dreaded: QUILT MATH.   Not regular arithmetic...it looked like a quadratic equation.

Cue the high-school-math-related PTSD. [And I attended a nationally known Math & Science high school in the nations largest city, sorry Mr. Fisher - Hello!! #Stuy84].   But,  I never got a chance to actually  try it.

When I was invited to the Back To School Blog Hop,  I suggested a post about "The Diagonal Piecing Method" for quilt backs.   Note to self: stop volunteering!!

In it's most basic form, the "Diagonal" method involved cutting a length of fabric diagonally, sliding the halves and sewing it back together in a wider size.    Kind of like a "Z-plasty" done by cosmetic surgeons.



Because most quilting fabric is 44" wide off the bolt, quilts wider than 40" or so will require either a special wide-with fabric, or....piecing.  Especially if the quilt is being sent to a long arm quilter, who will ask for about 4" extra on each side to load the quilt properly.  Some people  "just do it, others create a reliable, tested solution.    The original quilter to quantify this concept was John Flynn, and his post provides a detailed description, diagram and printable instructions here.

In my research, I came across two very different blog posts I found helpful.  If you are thinking about trying the "Diagonal" method for the first time, I suggest you check them out.

My friend Ebony Love discusses her take on this method here. She adds what I think it an intuitive and quite obvious solution that avoids most math!!!!   I think this is a great idea if you have some orphan blocks or extra top facbric you want to include in the back.    And, did I say, virtually no math?

Kathy Mack of   Pink Chalk Fabrics described her experience with the method here.  She raised some very good issues with regard to fabric choice that would definitely save the beginner some time and anguish.   She provides step by step photos, which were very helpful as I tried to work through this process for myself.  Kathy discusses her results and process in a straight-forward and easy to follow manner.

I learn better by doing (kinesthetic) than reading (visual), so I decided to try this out on a very small scale.   For illustration purposes, here's a fat quarter:

And here is a fat quarter on "the Diagonal": 


As you can see, the fabric expanded by 10" in width, but shrunk by about 9" in length.

The purpose of Flynn's equation was to determined the length of fabric (LOF)  needed to create a finished backing of the desired width.    The best example is using a standard 44" wide quilting cotton, what length do you need to create a backing of "X" width.    "Simply"  plug in you dimensions to the formula, crunch the numbers and you can calculate how many yards are needed. 
[easier said than done - it's been over 30 years since I finished Algebra!!!!]

For example, if I need a 60" wide back from my 44" wide fabric...and I only have 1.5 yards, do I have enough?     

But I think the power of this equation is even larger than that.   If you know any 3 of the 4 dimensions, you can solve for any variable.   Thus, this formula can be used to figure out how wide you can make one yard of fabric.....or any of the variables.    

Or, if you're brave, you can just slice, and slide.

So, final answer: Yes, it works.

Pros:
- use your stash
- less bulky when quilted
- inconspicuous if using a solid or blender fabric
-you can get creative with it

Cons:
- bias sewing
- could require math
- not appropriate for obvious prints or directional fabrics
-more challenging for larger quilts
-did I mention...bias sewing?

So, welcome "Back to School"!!   I hope you'll think about stretching your wings and trying this method if you haven't before!


My worthless Studio Assistant, Betty



















11 comments:

  1. I like this idea very much and I plan to try it in the future. Thanks!

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  2. Interesting. I'd never even heard of this before.

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  3. I love this John Flynn method and use it all the time. A friend even converted the formula into a spreadsheet to reduce all the errors.

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  4. I've heard of this method a long time ago and I will read your linked articles carefully. I think the reason I've never tried it is that I've always assumed that inserting a piece of straight grain fabric on the diagonal of the back would make the back stretchy and wonky due to the resulting bias grain. I'd love to try it on a small project to see how it works. Thanks for your collection of links on this topic!

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  5. Hi Peta! I'm following along the hop and am excited about how much there is still to learn!
    It never occurred to me to do this with a backing fabric. I can see how it would be really helpful if you don't think you have enough fabric for vertical strips to make up the quilt width. Thank you for sharing - it's definitely an intriguing idea! I'm not afraid of a long bias edge as long as I can starch the bejeebies out of the fabric first.

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  6. We have started using this method with our charity quilts for Project Linus. There is an online calculator that does the math for you and here is the link:
    http://multi-patch.com/html/diagonal_backing_calculator.php. Love this method!

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  7. Hi Peta! This was interesting! Thank you for for all the info and links. I'm really out of maths, but may need to try this. x Teje

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  8. I have read all the links and looked at the pictures. I am still a little confused. Do you end up with 2 big weird triangles left over? I'll have to try it on something small so I can see it in action.

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  9. That's very interesting. I hadn't heard about diagonal piecing on the back, but it makes sense.

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  10. Interesting. I have not hear of this, guess I'm a bit out of the loop. I'll keep this in mind for my next quilt back.

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  11. I love learning new techniques! Thanks for the info.

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