I have this jacket pattern. In case it's relevant, I'll be making it in a medium weight twill. I'm also adding a lightweight silky lining to give it a nice finish and make it easy to put on.
In planning my jacket, I thought perhaps I could make it warmer by adding some sort of fill in between the outer and lining, but I've never made a puffy jacket like that before and don't know what to use. Most search results just discuss how to select a coat for purchase, not how to make one.
I have some poly fill that I've used in pillows and stuffed animals - is that suitable for apparel also? What about batting, like for quilts? Or is there something else that is typically used?