In his final Narnia book, The Last Battle, published in 1956, CS Lewis betrayed every teenage girl with the line: “Oh Susan! She’s interested in nothing nowadays except nylons and lipstick and invitations.” With those words, Susan was gone, a lost cause, condemned by her legwear.

This month marks the 75th anniversary of the first limited production by DuPont of nylon stockings, and though Lewis has his fuddy duddy disdain for them, I’m going to claim a bigger and better significance. Nylons (and later tights) meant the democratisation of women’s legs. Until they became widely available in the 1940s, there had always been a sharp division between silk stockings and cheaper, more hard-wearing ones, made from cotton and lisle (respectable) or fake silk (dubious).

In Ulysses (set in 1904, published 1922), either James Joyce or Leopold Bloom has a lot to say: there’s Gertie and her stockings, Zoe and her garters, the display of “rays of flat silk stockings” in the department store and Molly Bloom’s “silkette stockings”. This was a silk-effect material, which AA Milne noted as inferior in his 1922 crime story The Red House Mystery, when a shopping trip to buy silk stockings for his sister throws the jovial narrator into a fret: “Could I be sure I was getting silk and not silkette … ?”

In her memoir The Laughing Torso, Nina Hamnett has brightly coloured stockings in pre-first-world-war Paris, and some with chessboard squares. But she tells us that Gertrude Stein wears grey woollen stockings (she was a bohemian, you see). And Hamnett herself lamented to a market seller that she couldn’t afford silk. He said it would be “an investment”, and she was “flattered that he mistook me for a lady of loose morals”.

“Art silk” stockings are much mentioned in books of the era, and I can’t be the only reader who initially thought they were particularly fancy ones – perhaps with a nice design on them. But actually it was short for “artificial silk”, as is clear from Rose Macaulay’s 1926 Crewe Train, where we get the thoughts of an unconventional young woman:

“You must, for instance, spend a great deal of money on silk stockings, when for much less you could have got artificial silk or lisle thread. Why? Did not these meaner fabrics equally clothe the leg?”

But then there are times when it’s the silk stockings that are wrong or common: you can turn to Agatha Christie for clarity on this distinction. There’s a lower-class young typist in the Parker Pyne Investigates collection, who is “all lipstick and silk stockings and curls” – with ideas above her station. And when the posh girl ups sticks to the country in The Moving Finger, her brother points out that really she should be wearing old, thick stockings, not silk ones, to fit in with the county set.

In Mary McCarthy’s The Group (written in the 1960s but set in the 1930s), one woman is advised by a doctor to dress up in “black chiffon underwear and long black silk stockings and some cheap perfume” to solve her husband’s sexual problems. It doesn’t work, and her husband objects to how much money she has spent at Bloomingdale’s. But the getup is plainly meant to look cheap and tarty, not upmarket.

During the second world war, stockings of any kind were hard to come by, with two important results: women wore makeup on their legs (see Westwood by Stella Gibbons), drawing back-seams on their legs in gravy browning; and US military men with access to supplies of nylons were able to entice British girls. In Roger Bax’s routine thriller Blueprint for Murder, a young woman says of her American soldier boyfriend: “It was him that gave me these nylons.”

No longer a class marker … Punk’s legacy to legwear Photograph: Mr Hartnett/Paul Hartnett

When the war ended, limitations on production went too, and nylons became the norm. It was a huge change: at last, everyone was wearing the same. Nylons were desirable, affordable and (relatively) durable; distinctions in stocking prices and appearances would continue to exist, but they would not be so marked. The idea of mending and darning stockings disappears from books. References to stockings become neutral, non-judgmental. In Gladys Mitchell’s 1955 crime novel Watson’s Choice, there’s a corpse in nylon stockings, to be checked for mud and rips. Barbara Pym’s heroines are still rinsing their stockings out in the sink through the 1950s. In Stella Gibbons’s Starlight (1967), drapery shops sell “knitting wool and nylon stockings”.

There’s a cheery, sexy 1968 novel by Jane Gaskell called All Neat in Black Stockings – it was made into a film with Susan George – but by then, tights were starting to take over. They had always existed, but as something worn by theatricals: in Noel Streatfeild’s Ballet Shoes (1936), Pauline and Petrova Fossil wear “skin tights all over” – more like a body stocking – to play the fairies in A Midsummer Night’s Dream. (Nana, of course, disapproves: “Might just as well send them on the stage in their combies,” she says.)

It took improvements in manmade stretchy materials to make tights into everyday wear – the next big advance after the invention of nylon – so it was no longer a problem keeping them up. In fact many authors use “stockings” when they almost certainly mean tights. “Hose” is a genteel archaism for stockings. I think this information is necessary because younger writers (or men) often don’t appreciate the differences – Amor Towles in the 2011 novel Rules of Civility has a young woman in the 1930s pulling her hose down to go to the loo, which is wrong.

At the other end of the spectrum Viv Albertine, in her recent memoir of her punk days, Clothes, Clothes, Clothes. Music, Music, Music. Boys, Boys, Boys, remembers this from 1977:

“Just as we’re about to go on stage, I look down and see that one of my brand new rubber stockings has a rip in it, all the way from my knee up to my thigh. … A roadie, seeing my distress, leaps to the rescue and tapes up the slash with a long strip of black gaffer tape. Looks quite cool.”

And so she creates a look to be copied … Stockings will never go away, and still might indicate cool, but surely will not ever be quite the excruciating class marker they once were.