JK Rowling and her millions of fans love details the way Hermione is fond of being top of the class. Those wishing to find out, for example, the provenance of Harry Potter’s invisibility cloak can read chapter and verse on it at the author’s Pottermore website.

With all due respect to the fabulous JK and her army of darling lawyers, I would hereby like to challenge the garment’s singularity. Far from being unique to Harry, almost every woman in the world, if she is beyond a certain age, possesses such an item.

The latest to don one is Mary Beard, the historian and presenter of the BBC series Civilisations. It emerged this week that Beard had largely “disappeared” from the version of Civilisations shown on PBS in America. In her place was a voiceover from the actor Liev Schreiber. The same had happened in the programmes hosted by David Olusoga and Simon Schama, but not, said Beard, to the same extent.

“I think I’m the most striking casualty,” she told The Times. “I wonder why that was?” On Twitter she pondered: “Can’t help think that a slightly creaky old lady with long grey hair isn’t ideal for US TV?” For its part, PBS said the US version was always going to be presented differently, including more use made of American academics.

Beard did wonder if she was “smelling a rat where there isn’t one”. The classics professor certainly has more experience than most when it comes to rodent detecting. From the moment she went mainstream on television her appearance has often attracted more comment than what she is saying. The late (and largely great) AA Gill was the first to pillory her for what he thought was her terrible hair, “corpse’s teeth”, and awful dress sense. All told, he reckoned she had no place being in front of a camera.

Beard hit back, questioning the size of his intellect, and concluding: “It seems a straight case of pandering to the blokeish culture that loves to decry clever women, especially ones who don’t succumb to the masochism of Botox and have no interest in dyeing their hair.”

Though Beard won that battle she has fought many more since. A single appearance can bring fresh waves of abuse centred around her age, looks, and sex. It is almost as if it is a crime to be a woman of a certain age. No wonder so many put on the cloak of invisibility and shrink into the background.

It is not always a choice. For the most part, the cloak of invisibility is thrust upon the wearer. It comes with the territory. A woman hits 40 and the garment arrives. It flies on to her shoulders, like some anti-Cinderella dress, as she walks out the door. People barge into her on the street as if she wasn’t there. At work, in meetings, she hears herself saying things, but the words seem to disappear into thin air until a man retrieves them and presents the thoughts as his own.

When our invisible woman goes home, she sees no-one on television who looks like her (unless Mary Beard has sneaked past security again). Same goes for the newspapers she reads, the clothes shops she tries to buy things from, the employers offering jobs. She is sure that she exists – the state is still taking taxes from her – but as a shadow of her former, younger, self she has become a ghost.

Do men of a certain age undergo the same process? Maybe they get an anorak of invisibility instead of a cloak. Perhaps it is just part of the ageing process, the obvious consequence of being part of a species that has always placed a premium on youth, vitality and fruitfulness. Whatever, it seems a pointless waste of talent. It need not be that way.

Just as JK Rowling has her fans, so does the blessed Mary Beard. As one of them wrote in praise of the historian’s television appearances: “Imagine, a woman over 30, valued for her knowledge and expertise, given visibility and recognition as an authority in her chosen field. Seems like it should be standard.”

Doesn’t it just? There is something that can be done about it. Women and men of a certain vintage could take to carrying around a large bell to draw attention to themselves. Frankly, though, my handbag is heavy enough already.

Alternatively, the first step to becoming visible again is to start picking out each other for recognition. See someone wearing a cloak or anorak of invisibility? Make it disappear from their shoulders by saying “Hi”. Tired of a colleague talking over others in meetings? Shush them. Shops not stocking items you want to wear? Complain. Let me know how you get on. Yes, you. I see you.