Of all the clothing categories, the cocktail dress must be one of the most old-fashioned. Not quite as bad as a corset or a crinoline – people do still wear cocktail dresses – but it’s not a cool thing to put on. Even a proper gown is more modern: you can dress it down with simple hair, flats and no makeup and look very zeitgeist-y. This is much more difficult to achieve with a pretty and rather formal little dress.

Unsurprisingly, I still wear them. When they aren’t too revealing, I often wear them in the office, as I sometimes dress up for work to a ridiculous degree. What I mean by a cocktail dress is a dress with something extra – maybe it’s a luxurious fabric that sets it apart or a bright colour or a slightly more couture shape. In my mind, the length of a true cocktail dress is around the knee: longer than a mini, shorter than midi. Google tells me a cocktail dress is “a smart dress suitable for formal social occasions” and I guess that’s broadly it, although this definition would potentially disqualify the dress in this post…

I am not on a mission to convert people to wearing cocktail dresses. Frankly, in most cases you’d probably be better off with an interesting skirt or silk trousers or indeed a dress, but of a more casual nature. It does not hurt to have one or two in your arsenal, though, especially if you do occasionally frequent traditional social events where people aren’t entirely aware that pyjamas are THE THING to wear these days.

A cocktail dress is not something you need to buy every season, it is much more important to find a colour and a shape that flatter and when you do, you’ll be good for years. I’m comfortable in a wide range of colours, so I’ve got a red cocktail dress and a pink one (or two…), a blue and a green and a sequinned one and surely several others that I’ve forgotten. And yes, I do own a couple of Little Black Dresses, but this is a separate category for me; I feel that a cocktail dress should look happy.

This burgundy number by Ketlin Bachmann is the latest addition to my collection and possibly the only one I wouldn’t wear to work. As soon as I saw it on the rail, I knew it was for me – I like both the colour and the shape. It’s a bit trickier than most dresses as it’s best worn without a bra, which I don’t mind, but others might. The applique deer add a light-hearted touch and the modest hemline balances the revealing top half to some extent (it occurred to me too late that the pictures don’t show the back which is pretty much fully transparent).

Actually, come to think of it, I might just add a nice little knit and wear it to work after all…

Dress by Ketlin Bachmann, earrings by Roxane Assoulin, shoes by Prada. MUAH Grete Madisson, images Laura Nestor.