Quote Originally Posted by HeathBar View Post
Is this a vest/waistcoat that you are going to wear with a jacket? If so then go with Zardoz's suggestion and match the lining material. If not, then I would make the back out of the same material as the front.
That's what I would do too. A waistcoat looks a bit 'unfinished' to me when worn by itself, if it has only a silk (or other lining material) back. I believe silk is usually used for the back so that you don't get friction between it and the inside of a jacket. But without the jacket, that issue goes away, and I think it looks better to use the same material as the front. That's just my opinion, though, and I've certainly seen a lot of folks running around with a waistcoat, sans jacket, with a silk back, so apparently that's not 'wrong'.