I'm trying to make my sighthound a satin lined martingale collar. I can easily make the collar but lining it with satin has proved to be way harder than I suspected.

I can't get it to stay put and hug the webbing when I'm sewing it, and the end product is loose satin wrapped around the webbing instead of nice and snug.

I've tried pinning it and ironing it and somehow it just refuses to bend to my will. It's never snug.

Are there tricks to getting a tight edge with this fabric? Help please? I feel like this shouldn't be as hard as it is, haha