In the previous post, I showed you how to make continuous bias binding.
The technique is great, but to really benefit of it, you should know how to calculate how much fabric you need to make the desired length of your binding.
I am glad to help you with this; I did the math for you, I made some cheat sheets and I also shared the formulas with you. You can download everything at the end of this post.
Replacing squares with rectangles
As you see, this formula gives a square fabric piece to work with. But what if you don’t have enough fabric for a square, and you have a rectangle instead?
You can replace the square with a rectangle. You just have to keep the same area of the fabric piece.
Here is an example:
The area of a 18’’ x 18’’ square piece of fabric is 18 x 18=324 square inches.
If you have a piece of fabric that is 42’’ wide, here is how to calculate the size of the rectangle:
324/42 = 7.714, so a 8’’ x 42’’ rectangle.
So a 18” x 18” piece of fabric produces the same length of binding as an 8” x 42” piece. I put the math to the test! See below!
- I received a message from a quilter who said that she does not understand how to make bias binding from a square piece of fabric. So check out the pictures below.
You have to cut the square diagonally.
Move the triangle as shown. This is where you could mess the thing! The new shape must be a parallelogram (bias edge parallel with bias edge and the straight cut edges parallel) – pay attention to this step and half of the job is done.
Next: you draw lines parallel with the bias edge – at the desired distance (the width of your binding). Stretch the edge to make sure it is the bias edge.
You will join the straight edges, so draw lines at 1/4” from the straight edges.
Here is how to offset the edges…
and how to pin the edges.
And here is the rectangular piece turned into a parallelogram,
and the straight edges you have to join.
If you do this for the first time, you may think it looks weird and can’t work, but I assure you: it works. Just match the points (don’t forget about the offset) and you will end up with a beautiful tube!
It looks like it is easier to join the edges of the squares than the edges of this extra long rectangle, but in reality it’s the same thing.
I hope this helps and the long explanation doesn’t make you think it is too hard to even try it! The cheat sheets will help for sure!