Richard Nicoll, SS11, London.
There are many ways that fabric edges can be finished so that they do not fray, and bias binding is one of the most popular choices for fine fabrics.
Essentially, it is just a strip of fabric which is folded and sewn around the edge of the fabric that leaves the raw edge of the main fabric neatly encased inside. It is sewn in such a way that both the raw edges of the bind itself are also folded to the inside, which all helps to create an edge finish which looks very neat from both the right and the wrong sides of the fabric.
The examples above and below show how the edges of necklines and armhole hems have been bound in the Richard Nicoll collection from Spring-Summer 2011.
Other types of binding can be done using other materials as discussed in a previous post Garments Bound in Grosgrain and Leather».
The technique used for the Richard Nicoll garments above requires a different method, and is specifically based on using bias cut strips of fabric. The success of a bound edge is very dependent on cutting the strips on the correct grain. So for some materials such as leather the direction of the strips will not have as much effect, but for woven fabrics such as an organza or silk satin, the strips will need to be cut on a perfect 45 degree angle to the selvedge. This is also know as cutting on the bias. For further explanations of different grainlines you can refer to this post Explanation of Grainlines».
The below examples show how strips cut at different angles will respond to being placed around a curve. Often bound edges occur on a curve such as a neckline, and so will need to be cut on a bias grain in order to be shaped correctly. But even on straight edges, a bias cut strip of fabric will allow the machinist greater flexibility, as the bias will have better give. When in doubt, always do small tests to see what technique will work best for your design.
Some strips of bias binding will be cut out of the same fabric as the main sections of the garment and in these cases strips can be cut from a larger piece of fabric. In this situation you will need to cut strips on the bias from your fabric at a width that is roughly just over 4 times the finished width of your bind. For example if you want to have a finished bind of a 6mm border visible from the right side of the fabric, then you will need to have a 25mm width strip of binding. It will be easiest to get an even bind if you press folds in your binding first before stitching onto garment.
At other times it may be suitable to use a pre-made bias binding, which comes on a roll and will be pressed so that it is ready to be sewn into position. The images below show the wide variety of bias bindings which are available in a array of fabrics such as cotton, polyester/cotton blends, silk georgette, linen, corduroy and foiled lame and which come in a variety of colours and widths.
Examples of pre-made bias binding, available from MacCulloch&Wallis».
Below are the instructions for how to attach your bias binding to your fabric:
Catwalk images from Vogue.co.uk»
Bias binding images from MacCulloch&Wallis»
Technical images from TheCuttingClass.