Making your own bias binding is easy-peasy! I don’t know why everyone doesn’t do it! It gives you the perfect way to finish any neckline (or anything else that is on a curve for that matter (like armholes, curved hems, appliqué pieces).
Bias biding, usually bought from any haberdashery shop, can be made from the fabric you have in stock. Scraps of satin, lining fabric, in fact any woven fabric (it doesn’t work with felts and knits). But best of all, the leftovers matching the garment you are making will make perfect bias binding and give your garment a lovely finish on the inside.
Just lay your ruler diagonally on your fabric at a 45 degree angle to the direction of the weave. Draw out out your strips – the width of a standard ruler is about right. Cut yourself some long thin strips, about 1.5 inches wide, out of the fabric.
You need to join them to make one long piece of tape. The way to do this is shown here: lay them, right sides together, at 90 degrees to each other and sew at 45 degrees, so that when you fold it back it makes a straight line of fabric. Then iron flat. And there you have a curvable, stretchable matching tape for anything you care to make! Easy!
Have a look at my post about how to cut fabric on the bias