Sheen and fabric

One of the issues I've identified in my wardrobe is that I'm drawn to simple cotton tanks and shirts, which I like to layer under cardigans. That's fine in itself, but ribbed cotton tank tops have a way of looking casual. For example, I have a dark purple tank top, kind of grape-y. It's a nice touch of color, but a better alternative (for work anyway) would probably be a dark plum silk or rayon top with some sheen or detail. The cut could be the same, but the difference in sheen and fabric would give an outfit some interest that simple cotton just doesn't have. So some of the items I'm looking for are shells or tank tops with a nice fabric, interesting color or detail. I have some kind of aversion to blouses in general, which sometimes makes it difficult to look polished. So a blouse or two is on my list also.