Satin panties DO show under clothes, especially tight-fitted clothing. This is why satin panties have mostly disappeared from most mainstream department stores (when they were everywhere in the 1990′s)…more women are concerned with visible panty lines (lots of attention to this on tv and in magazines in the past decade). Satin (polyester satin, charmeuse satin, etc.) has a “high molecular weight’ which means that it is thicker than most fabric weaves. The ends of satin (where it is cut at the waste and legs) frays easily, and can not be flattened into an “invisible seam”; the ends have to be tucked-sewn or ruched around the seams (and especially the elastic bands)…there are some boutique satin panties that do not use elastic at the seams, bu these tend to be looser and still show….anyways, this is why the seams show through. And the material itself is “liquidy” and a bit loose, so the material is sometimes detectable as well. Women who still wear satin panties either don’t care about VPL (getting rarer), or, they wear them under loose jeans or a-line skirts or dresses (and with underskirts or petti-slips). Find a girl who wears a-line skirts (pleated or tiered skirts are good for hiding), or frilly dresses, and chances are, she still has some satin panties (or even ruffled panties) she loves to wear under them.