I don't know about never. My husband has a couple of suits with pants being lined front of the legs till just over the knee.

If you are making something with wool I would make a fully lined garment. Wool is itchy on the skin and that can irritate some people. I also fully line when making with wool.

Interesting! Can I take a guess? Men's wool suiting is rather "harder" than the softer wools women usually like for pants. Since men's suiting seems to be a tighter weave, giving it a crisper feel, perhaps the lining is not needed so much. Looser, softer weaves would tend to bag out more. Now, that is just a guess, remember. I'll look forward to see what others have to say. Hugs, Marji

Chenille, I do believe it has to do with the fabric's that are used or the delicate skin of a woman - Hehehe! Just kidding! *4U

Hi, yes my son has several pairs of trousers only lined at the front and to just below the knees, so who knows, maybe it would also be up to the individual and yes I agree that the softer fabrics would definetly sag more especially on the sections that would have alot more pressure put on them, hope you find your answer, Sheryl

Since I'm alergic to wool, I can only assume leaving them unlined would be to torture them. Just like hanging them with a necktie. LOL