Bias binding is necessary if you ever want to make a quilt with a scalloped edge, and it is a bit laborious to cut, vs the usual straight grain cuts. I have made one doll-size scalloped edge quilt ever, and used a fabric that occurred elsewhere in the quilt, so probably wouldn't have bought ready made binding even for that, but it's kind of nice to know it's out there if I ever get lazy or rushed. One thing someone pointed out about bias binding is that it wears better than straight grain. If there's a thread that runs along the edge of your quilt it's more likely to make a long tear if it breaks whereas a bias results in a crisscross pattern of threads all along the edge, and if one thread breaks it only goes a few inches.

I love stripes on the diagonal for binding, so often make my own bias binding - even though I don't need it to be bias for the give for scallops or other rounded sections. Easy to make and looks so nice!

That binding would be too narrow for me. I cut my binding 3" wide and use a 1/2" seam when I sew it onto the quilt. That makes the edge of the quilt fill the binding and I like the looks. I learned this method from Philippa Naylor's Quilters Question Time.

When I began quilting and took classes way back when, our instructors taught us that bias binding was the thing to do, so my first several quilts were bound with bias binding. I used the continuous binding method, which I enjoyed making for some reason, so it was no big deal. After a few years I realized that bias wasn’t really needed on the straight edges, so switched to the straight method. I could tell no difference between the two types after the quilts had been put into use.

I love the stuff. Who cares if it is bias or whether or not you “need” bias. It is ready to sew to the quilt! No million joins or endless sewing lengths together and pressing seams. I buy it when Green Fairy runs their very good sales.