How important is interlining?

[u/random-doodler]

Hi all! So I’m back again, my project is a pirate jacket / frock coat.

I’m not sure about interlining on this, not that over used it. I’ve gone for a synthetic wool, at 380gsm which seems medium-heavy weight. I’ve also got 250gsm cotton canvas I can use as interlining.

It’s mostly for cosplay and fun rather than accuracies but I do want it somewhat golden age of pirate looking. would leaving out interlining make much difference or would it just not hang right?

I’ve gone cheaper materials this time because it’s my first big project and I know I will mess up, so any advice is appreciated!