Diagonally Seaming a Quilt Back

The first big vacation my husband and I took together after the kids were born was to England in 1989. Dad and Mom watched the kids and we had a wonderful time. I was a beginning quilter and really had my heart set on shopping for fabric at the Liberty store in London. It did not disappoint. The store itself was beautiful and the fabrics were lovely. When I finally decided on my favorite and asked for a meter to be cut, Mike responded with “We didn’t come all this way for 1 meter, what else do you like?” So I happily left with 3 meters of lovely cotton in a purple bag. Every so often I’d take them out and pet them, then put them away. They were “too special to use”. Over the years I’ve collected some additional small pieces of Liberty fabric too (and they all went in the purple bag).

So now I’m signed up for a trip to the Birmingham quilt show and I decided it was time to finally use my “Liberty” to make a tote bag (so I won’t feel guilty buying more 😊). I chose a favorite pattern and added a few fabrics to the three original larger pieces in the bag (the remaining small pieces will be used in a pre-trip project ~ watch for them in a future post).

Years ago I was gifted a tote bag that I’ve used many times. I loved it so much I bought the pattern, and was delighted to discover that is was written by my friend Linda Marcou! It was time to pull it out and use it for my Liberty tote.

I needed to start by making a quilt 37 1/2″ square.

The burgundy color piece of liberty would make the perfect lining, but it was only 36″ x 40″. Could I use my friend Lori’s trick from a post a few weeks ago (click here to read that post)? I gave it a good press:

Cut the diagonal:

Slid the halves in place:

and discovered the answer was “no”. My original piece was too small. But Lori had mentioned that a diagonal strip could be added to make it a bit bigger.

After figuring this out my friend Sue, of Aunt Susie’s Longarm Quilting here in Watertown, just happened to send me the instructions she uses for diagonal seaming the back of a quilt. They are originally from John Flynn. This may make some of you go cross-eyed, but I’m putting it in this post for those who find it helpful ~ AND for me to refer back to when I can’t find these instructions elsewhere 🤣. If this isn’t for you, please just scroll down to read about finishing the tote at the next ***.

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At first read I was a bit confused. Then I reread the part on the diagram in the upper left that said it was two layers of the backing fabric, both facing up. OK ~ but how much backing fabric do I need to do this? As I pondered this question I received a second email from Sue with the answer, and here it is:

John’s method for diagonally piecing a quilt back from one piece of fabric is the most efficient way to make the back whenever the width of the quilt back is 1 1/2 times (or less) the width of the fabric you want to use. For example, if the width of your back fabric is 44″, use John’s method whenever the width you want your back to be is 66″ or less. If you are using fabric that’s 60″ wide, use John’s method whenever you want your quilt back to be 90″ or less.

John has come up with a formula to figure out how much fabric you’ll need to diagonally piece the back. It looks like scary math at first, but if you simply plug in your own numbers (and use a calculator 😁) it’s really quite easy. Here’s the formula:

and here’s the example that will help to make it all clear:

We want to know how much 44″ wide backing fabric to buy, so WF will be 44″, and LF will be the answer to our equation.

Let’s say your quilt top equals 48″ x 60″, and you want your quilt back to be 51″ x 66″.

In the formula LQ = 66″ and WQ = 51″

When all the numbers are plugged in for this example the equation looks like this:

At this point I grab the calculator and find that 66 x 7 = 462. The fraction on the lower right means 462 needs to be divided by 37. I grab the calculator again and find that 462 divided by 37 = 12 1/2.

The last step is to add: 66″ + 12 1/2″ = 78 1/2″. I’d round up to 80″. This is just under 2 1/3 yards, so I’d purchase 2 1/2 yards just to be safe 😊.

Thanks so much Sue, I think many of us will find this helpful.

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It was too late for me to use this formula for my current project, so I added a 6″ strip to the triangles and the lining was ready.

I layered it with a piece of batting, and stitched strips on “quilt-as-you-go” for the outside of the tote.

Once the quilt was quilted and bound

it was stitched into a tube,

the straps were added, the entire piece was folded, fronts sides together, and stitched along the sides.

When I chose the layout for the outside of the tote I had envisioned the outside looking like the photo above, with the burgundy on the inside of the bag. When the “tricky” sewing and folding was done, I was surprised to find the inside of the bag looking like the previous photo, and the burgundy fabric was lining the side pockets.

The outside of the tote ended up quite different from what I’d imagined, but I love it!

Now it’s ready to be packed for our adventure in Great Britain!