What fabrics make me think of affluence and prestige? Is it fiber-specific, or related to the construction of the fabric itself?
This has changed over the centuries. Linen used to be the fiber of common garments, while cotton was more expensive. Thanks to the cotton gin that’s been reversed. Man-made fibers, polyester being probably the most obvious example, started out by being desirable, space age-type stuff. Then people realized they weren't that awesome because they didn’t breathe as well and were uncomfortable to wear , even if they were easier to care for than natural fibers.
Then the fiber groups improved the technology, and now we have polyester that looks and acts like silk for a fraction of the price. Now man-made fibers are cheaper and more widely used, so the natural fiber groups have had to wage huge campaigns to get people to use their fibers again. I don’t care how expensive it gets or how cheap man-made stuff gets, there is still nothing that breathes and wears like cotton. At least, nothing yet.
The typical reaction is to say silk = affluence, since it’s used so much in couture and is such a pain to harvest and use. Maybe it’s satin in general that connotes affluence as well, although to me the shinier the satin, the cheaper it is. (Definitely an opinion formed in my early cosplay days, where so many cosplayers used nothing but cheap costume satin for everything, even when it was completely the wrong fabric to use.) Oh, and I’m not a fan of shantung or whatever the slubby stuff is called. Yes, I know the look is deliberate, but it looks imperfect and of lower quality to me than “perfect” bridal satins and stuff.
(Back to the whole simplicity and minimalism in my designer statement there. Slubby silk is too unpredictable; smooth silk is orderly and practical. OCD OCD OCD.)
Maybe the “real” affluence is in fibers that have yet to gain wide acceptance. Things like bamboo, coconut, banana leaf, and other green/sustainable fibers. "Green" pretty much guarantees that they’re expensive, and they're all a little exclusive, so I guess you have to be rich to get garments made from these.
But from what I’ve felt of them, they’re incredibly nice. The hand is amazing, and the properties are useful.
This amuses me because in The Five Star Stories, most of the characters wear clothing that is entirely produced from man-made fibers. They’re so much easier and cheaper to produce and require factories instead of farming, so the whole civilization changed over to that a while ago to make things more efficient to produce. Man-made fibers are seen as the norm; natural stuff is undesirable and a symbol of outdated ways of life. Ironically, fatimas have such sensitive skin that they can’t wear man-made fibers; they have to have things like silk and cotton against their skin or else they break out in bleeding rashes. But, the fatimas are kind of products of an earlier time in the cultural development…while they and the headdliners are still needed to protect ordinary citizens, they are seen by ordinary citizens as odd, distasteful, and a product of a bygone era. Hm.