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