Of hosiery The Bombshell Manual Of Style says:
It’s no stockings and a naked leg or a garter belt and stockings. These may be silk or nylon, seamed or not. Climate has nothing to do with the Bombshell’s decision to wear stockings or go without them.
Dream stockings are not made of silk, but of nylon. (True vintage glamour girls know this and it’s a glaring sign of ignorance or down-right posing — but not pin-up posing — when they do not.) Ever since nylon stockings were created, they’ve shown-up silk for many reasons, the best of which is their fit: nylon does not ‘pool’ and bag as easily as silk hosiery.
The best nylon stockings are fully-fashioned. This is not an arbitrary name like ‘best’ or ‘improved’ to flatter a product; fully-fashioned stockings are knit on 3D machines — shaped to fit a lady’s leg. Unfortunately, fully-fashioned stockings are not made in plus sizes for this reason.
Denier is a term to denote size or number of filaments in hosiery, like thread count for sheets. The higher the denier, the more sturdy & opaque the hose; the smaller denier, the more sheer the hose.
The welt of the stocking is the top where the garters are attached. Typically this is where the stocking brand, style, color lot, etc. information is printed. Many stockings, especially vintage stockings, also have welts with exquisite detailing.
Once again, sizing may be an issue when shopping for vintage stockings and it’s advised that you begin by measuring your legs. There’s an excellent guide for both measuring your legs and deciphering stocking sizes at eBay — it’s written by Steve of Stocking Showcase, who is as much a fan as an expert. Follow his advice, and you can’t go wrong.
If you’re not sure how to properly & safely put on stockings, you can — and should — read A Slip of a Girl’s Ultimate Guide To Putting On Hose.