Bias Bindings are one of those simple techniques that I often use to give my sewing creations that little extra touch - like the sleeve binding on my bicycle blouse. They are a way to add a subtle contrast to a garment and make them stand out, and they are simple to do! A bias binding is simply a strip of fabric that is cut on the bias. The bias gives the fabric a little stretch and enables it to gently curve around an armhole, neck edge or curve of a full circle skirt. First, a definition: a bias binding encircles the seam allowance. The binding shows on both the right and wrong sides of the garment and the seam allowance is not folded to the back of the garment, but stands straight up in the binding. If the binding is folded to the wrong side of the garment and doesn't show, that is a bias facing (another post for another day!). There are 3 different types of Bias Binding: Half Fold or French, Single Fold and Double Fold. Below I will explain how to make and apply each kind.
A Half Fold or French Binding has one fold down the middle with the raw edges even. A Single Fold Bias Binding has each of the raw edges folded into the middle and a Double Fold Bias Binding has each of the raw edges pressed to the middle as a single fold, but is then pressed again sometimes in half, but sometimes with one side slightly larger than the other.
Making your own bias binding is as simple as cutting a strip of fabric on the true bias ( a 45 degree angle) and pressing it. You can use a bias tape maker to speed up the folding and pressing part, but it really isn't necessary. To apply the Bias Binding, for both the French and Single Fold, the raw edge or edges are pinned to the raw edge of the right side of the garment that is being bound. For the French, both raw edges are pinned and for the Single Fold, one fold is opened and the raw edge pinned to the garment raw edge.
The binding is attached with a 1/4" seam.
The seam is slightly trimmed (don't be aggressive with the trimming - the seam allowance is supposed to fill the binding), and the binding is folded to the wrong side of the garment.
The binding is secured to the wrong side by slip stitching the binding to the previous stitching, or you can stitch in the ditch from the right side catching the binding underneath. For the Double Fold binding, the raw edge of the garment is slipped between the double folded edges of the binding.
The binding is then top stitched in place.
So which type of Bias Binding do you use when? The Double Fold Bias Binding has the advantage that it is applied in a single step, but the stitching is visible. Also, I find it hard to control on curves and often don't manage to catch the binding underneath. I prefer the control I have with the Single Fold and French and therefore seldom use a Double Fold Binding.
The Single Fold Binding results in 4 layers of binding and 1 layer of garment fabric. A French Binding results in 6 layers of binding and 1 layer of fabric. The goal of a binding is often to provide a little weight to the garment besides finishing the edge, so a French binding is helpful when using a thin fabric and you want to provide a little more heft. If binding a thicker fabric, the Single Fold is definitely preferred. I used a Single Fold Bias Binding to bind the facing of my Extra Sharp Pencil Skirt.
When making your own Bias Binding, the strip should be cut 4 times the finished width of the binding for the Single and Double Fold plus a little more for the turn of the cloth. For the French Binding, the strip needs to be cut 6 times the finished width plus the turn of the cloth. The amount you need to allow for the turn of the cloth depends on what you are binding! if you are binding a single layer of fabric, you really don't need to allow much for the turn of the cloth, but if you are binding the neckline of a smocked bishop, then I would allow at least 1/4 of an inch.
One other thing to note - if you are applying a binding to a pattern that does not call for it then you need to adjust your pattern. Remember the seam allowance or hem isn't turned to the wrong side with a bias binding, but its width still shows on the right side of the garment. If you are substituting a binding for a hem or on a collar on a pattern that calls for the seam allowance to be turned or hemmed, the seam allowance needs to be trimmed away before applying the binding so the original pattern lines are maintained. I hope you try adding a bias binding to your next project!