Oliver Wainwright

In the northwestern region of the Amazon rainforest, the Jivaroan tribes used to shrink the heads of their slaughtered enemies and mount them on sticks as triumphant hunting trophies. Sliced open to remove the skull, the flesh was boiled and mixed with hot gravel and sand, in the belief that the spirit of the victim would now serve the victor.

Latterday head-shrinkers can now be saved all that mess and bother by heading to Selfridges, where similar kinds of black magic are being practised in the pop-up iMakr store: there you can get yourself shrunk down and 3D-printed as a six-inch figurine. First launched in Tokyo's Harajuku district last year, in the cradle of teenage novelty trends, the phenomenon of the 3D photo booth has quickly spread around the world: the service is now offered in Walmart and will soon be rolled out in Asda stores, so you can pick up a self-portrait with your groceries, for around £40.

In Selfridges, iMakr's portraits will set you back £159 and up. "Ours is the latest technology," says Sylvain Preumont, founder of iMakr, as he ushers me into an octagonal Tardis, where 48 cameras await to capture my soul in 360 degrees.

Standing in the brightly lit booth, hearing the surround-sound of SLR shutters snapping simultaneously, feels like being in the middle of a paparazzi scrum, but one that might end with you being beamed to another dimension. Thankfully, you just end up on the computer. The photos are then mapped and joined together using software that generates a "point cloud" of your body, a kind of three-dimensional map of dots, before creating a polygonal mesh, like a digital chicken-wire model. After a few hours of processing and manual fixing – creating voids beneath skirts and inside jackets, where the cameras can't see – the model is sent to a printer the size of an industrial chest freezer.

In a similar process to ink-jet printing, a print head shuttles back and forth, spitting out microscopic dots of ink and binder, only instead of a sheet of paper, there is a bed of plaster dust. Each time the printer passes, another layer of powder is dragged across the bed, 0.1mm thick, until the model is built up – at a rate of 28mm per hour, taking around five hours to build a six-inch figurine.

Just like those rubber-moulded models beloved of craft shops, the printed figures are essentially just made of plaster of Paris, water and ink, the finished objects then dunked in a bath of super-glue to fix the colour and make them a bit more durable. Seeing yourself being extracted from a bed of powder is a surreal sight, like watching an archaeological excavation, knowing that you are the embalmed mummy lying beneath the sand. Your little body comes out looking like a snow-encrusted yeti, before an airbrush and paintbrush are employed to dust away the excess powder and reveal the multicoloured mini-you in all its disturbing glory.

Colours are still to be perfected – flesh tones verge on the corpsey, while my blondish locks came out black. But other details are remarkable, from the knot of my shoelaces to the moth-eaten hole in my jumper. Now all that remains is to work out what to do with this slightly sinister, staring miniature of myself, frozen in an eternal grin. It's freaking me out, standing watching me on my desk. I just hope there's some space on my granny's mantlepiece.

Sophie Heawood

The question of what to wear perplexed me. Should I test the printer and dress up like Leigh Bowery? Or turn up wearing nothing but a feather boa and a thong, as a friend suggested? I tried to invent an outfit that would both maintain my modesty and reveal my caesarean scar, as I was curious to see what the 3D printer would make of that red line of which I have grown so fond. Until it dawned on me that I was really just having my photograph taken, not auditioning for reality TV, so I went in my normal clothes. Which turned out to be the biggest mistake of all.

"Would you tie your hair back," said the Frenchman in charge of the studio, looking at my dark scruffy bob with a concerned face, "as hair that looks like – like yours … well. It will come out looking like a helmet. And your outfit! This is going to be interesting." Given that his prior instructions had said the computer liked details and pattern and colour, rather than solid black, I thought my candy-striped pink shirt would be perfect. And the trousers printed with little hieroglyphic people all over them. And the leopard-skin shoes and the wodge of red lipstick and gold chains.

It turns out, when he had told me to wear patterns, something had got lost in translation. What he meant was texture, like denim jeans or a knitted sweater. Still, they managed to make my mini-me, and it's certainly a fun thing to have. It must be, as everybody I've shown it to has burst out laughing. "You look so GRUMPY!" they say. (I was told to cross my arms!) "You look kind of sallow and DIRTY," they add, as my face is yellow and the clothes are all sort of washed in grey. "I can only tell it's you from the clothes, not the face," said a member of my own family.

I love the physicality of it, though: her tummy curves in just the way that mine does, the slight bulge in the calves is exactly right – the shape of it is me. My plan now is to get my little girl to pose for one every year of her life, and line them up on the mantelpiece like Russian dolls, to see how the technology improves as she grows. Although I worry that in about five years' time we'll have done away with these statues altogether, and my mantelpiece will be crowded with 3D holograms.

Stephen Moss

"Why would anyone want to have a statue made of themselves?" a friend asked me. "I can understand why you would want to have one made" – she is all too aware of my overweening self-regard – "but why would anyone else want to do it?"

It was a fair question, and one I put to mini-you guru Sylvain Preumont when I pitched up for my statue-making session. "Children will want to get one for their grandmother for Christmas," explained Sylvain, an effortlessly stylish and articulate French-born entrepreneur, "and then there are the people with a little bit of an ego."

I am definitely part of the second market. But there is a problem. I have turned up with a colleague from the Guardian – young, dynamic, smiley. He would easily pass for a member of One Direction. I feel ancient and dishevelled in his company. And there is a second problem. I have in part ignored Sylvain's instructions on what to wear. "Avoid plain, uniform colours, especially black," he told me in an email. "The software likes details and remarkable points." I have made a point of wearing a ridiculous pair of green trousers, but kept on a black jumper – supposedly slimming, you see. He makes me take it off. Now I look truly absurd: green trousers, red T-shirt, battered black hiking boots. I also have a cold and suddenly realise this is going to be a fiasco.

It doesn't help that I am too tall for the booth, so the top of my head will be sliced off. Sylvain and his assistant, Pankaj Raut, say they will rectify this by adding in the top of my head. I suggest superimposing the head of George Clooney on the body of Brad Pitt, but this doesn't find favour. "Perhaps we could give you a hat or a crown," says Sylvain, who is considering making a set of chess pieces from the 3D Guardianistas.

I try three poses, all hopeless: hands in pockets, arms folded, hand on chin to suggest deep thought. My cold is getting worse. Why did I agree to do this? A few minutes later, Pankaj shows me the pictures. They say the camera does not lie, so the evidence is unendurably brutal. My self-image is of a saturnine figure: tall, athletic, dangerous. So who is this grey, shambling old bloke dressed like a dustman?

I have seen enough. What on earth is the statue going to look like? Can I take out an injunction to stop the Guardian using it? I make my excuses and leave. "Perhaps you should have done it naked," says my friend when I relate my depressing experience. "Like Michelangelo's David after he's eaten all the pies."

Stuart Heritage

I've been in this position once before, and it was just as awkward. I'd returned from Seoul, where I'd been teaching, to find that the mother of one of my students had sent me a framed A3 pencil drawing of my face that she'd copied from a yearbook. It was a perfectly good drawing but what was I supposed to do with it? I could keep it, but that'd be an act of incredible vanity. In the end, I gave it to my mum. Which is just as vain. Perhaps more so. "You know what you need, mum? A massive picture of my great big face hanging on your wall for ever." She's still got it, to the eternal chagrin of my little brother, forever annoyed that a Korean woman didn't draw his face a decade ago.

So this gives me a feeling of deja-vu. I've got a little 3D-printed figurine of myself, and it is extraordinary. You can see tiny details, like the outline of my phone in my pocket. It's not perfect – my head seems proportionately very tiny, plus I don't appear to have any eyes at all – but it still looks a thousand times more like me than my Guardian byline photo.

But what to do with it? Put it on my desk as part of a larger shrine to myself? Give it away to someone whose life I wrongly assume will be improved by a tiny me forever blindly gurning at them from the fireplace?

It doesn't help that in both the drawing and the figurine I'm pulling the exact same pretending-to-think-with-your-fingers-on-your-chin pose that photographers apparently delight in forcing me into. Both times I've tried to subvert things by pulling a slightly funny face, and both times the end effect has been one of such colossal smugness that even I want to punch myself in the face.

Reluctantly, I think I'm going to keep it. If nothing else, in years to come it'll be a handy reminder of how terrible my dress sense was when I was 33. Perhaps it'll make a nice stand-in on a nativity scene – the Three Wise Men could temporarily become the Two Wise Men and That Eyeless Bell-End Doing the Annoying Thing With His Face.

Lucy Mangan

Here I go, stepping into the future. You make sure you are standing on your mark – the lenses are essentially focused on a column of space in the middle of the booth, so you can't pose with your arms out to the side or your mini-me will emerge partially limbless – and the cameras click. This must be what Z-list celebrity feels like. For a "civilian", as Brigadier General celebrity Elizabeth Hurley refers to normal people, it's an unsettling experience. I don't want a picture of me taken from any angle. I wonder who will actually take up the opportunity in a department store when they have to pay for the privilege of having their every flaw rendered in plastic for posterity? The aesthetically fortunate? The supremely self-confident? The tragically deluded?

I watch the computer screen as my "point cloud" is generated. Do you remember reading reading the bit in Charlie and the Chocolate Factory when Mike Teavee gets sent, in millions of tiny pieces, through the air to emerge on the TV screen at the other end? The mental image that conjured up is what I'm looking at now.

Gradually, a familiar figure takes shape. It's six inches high and has a slightly rough surface that, together with the fact that the colour of my green top seems to have bled into my face, neck and arms, makes me look as if I'm covered in a light layer of mould. As symbolic representations of the ultimate truth of existence go, it's not bad, but I'm not sure it's what I would be expecting had I got this done as a Christmas present for a loved one.

Apart from that – well, the figure looks five months pregnant even though it isn't and slightly melted. The back view is horrendous. Which is to say, it is completely accurate, a triumph of modern technology and it went straight in the bin.

• iMakr and My Mini Factory will be hosting a pop-up 3D printing store from 24 October at Selfridges, London W1