If you buy lining material get the heavier weight. If you don't want to go with lining material, you can line it with summer suiting or any fabric of that weight, that is mostly synthetic and has a bit of body. I say synthetic because it won't shrink like natural fibers do. It doesn't have to be a plain color, It can be patterned, striped or plaid that has a similar color in it. Though with plaids you will have matching to do.

Be sure to wash your material before you cut.

Thanks, oilpainter. Any specific fabric types you would recommend? Would china silk (poly), crepe-backed satin, poly charmeuse, or something like that be too flimsy? What do you mean by "summer suiting"? I've located some true lining fabric (flannel-backed satin) online, but it doesn't come in a good color for my coat.

The old lining is actually not horrible except for a big hole right at butt level! That took about 10 years to develop, so not too bad. I have relined the pockets a few times, though.

Do you have a fabric shop near you? I would take the coat in and look at fabric. I don't know which of those names would be good or if they are too flimsy. Don't just look at lining material but dress fabric too. What you are looking for is something that is a sturdy fabric that won't wrinkle or wear out fast. Something that is not bulky though or you will have trouble with it fitting right.

I once lined a jacket I was making with poly cotton. That jacket is 10 years old and the lining is still looking good.

If you can't find a good color match then go with a lighter mauve.

Success! I ended up getting a thin polyester lining material in a lavender color. It's not the nicest fabric, but because it was inexpensive I didn't feel too stressed about cutting into it. I bought 4 yards, but it only took about 3 1/2.

The project went smoothly. Everything fit together perfectly, and I even figured out how to sew the entire lining in by machine, including the sleeves. The original was not attached at the hem, so that made it easier.

My sewing machine does only straight stitch, so to keep the seams from raveling I double-stitched them (one line on the seam line, a second line 1/4" away) and trimmed close to the second line of stitching. I only used one line of stitching to sew the lining to the coat, however.

If I decide to redo this in better fabric, it will be easier and will not take as long now that I know how to do it.