Legend has it that the very first life models were five beautiful virgins who posed as Helen of Troy for the Greek artist Zeuxis. Disturbingly, the fifth century BC artist is said to have laughed himself to death while painting an old woman, who was sitting for him as Aphrodite. All of this and more comes to mind as my boxer shorts hit the floor.

It's not exactly cold, nor is it warm. I am standing behind a blue fabric screen in the Wasps artists' studios in Glasgow's east end. Over a slow cup of tea, the artists – two men and two women – have run through some facts, explained what they are working on, asked if I am nervous.

My experience as a life model, they know, is limited – the last time I was naked in front of strangers was as a baby, and I have little memory of that. I fold and refold my clothes on the back of a chair to the sound of easels being scraped across the floor. The artists chat sleepily about some documentary they have seen. I fold my clothes again.

My socks need to be arranged differently, I think; I should put them inside my shoes. My body looks white, even against the harsh white walls. I have been told to wait until I'm ready to come out, which at this rate could be several days. My first tentative step ends quickly: could I have misunderstood? Maybe I should be wearing a towel? I should pop my head round the screen and double-check, but a wave of nausea holds me back.

In researching this piece – ahead of the Scottish National Portrait Gallery's (SNPG) Naked Portrait exhibition, which opens in Edinburgh this week – I have talked to a number of life models, who strip either to part-fund their studies or as an alternative source of income. One of those, Jim Connelly, an otherwise unemployed 50-something, has been particularly supportive of my plight. I take another look at his text message: "Relax into pose as early as possible, focus on a point you can return to. Good luck."

Over the past week we have become well-acquainted. Connelly has been life modelling since April. He worked in the NHS until ill-health meant his job was no longer viable. The road back to full employment has been paved with monotonous clerical posts. "I get really pissed off sitting in an office with people talking about Coronation Street and EastEnders," he says.

"With modelling, there's more autonomy because I can make certain decisions myself." The standard going rate of £10 an hour is fine, he thinks. The hard part is getting the work. On average, he models for a few hours a week, sometimes less. He has the full support of his wife, the self-respect that comes from "not just sitting on my backside", and the mindset that life is for living. "It's not like I'm a porn star," he points out, "although there would probably be better money in it."

"You tend to strike up a good rapport with the artists and they really help you out," he says. "Modelling has made me realise I'm getting older and have a pot belly but you have to forget your vanities. Everyone's form and shape is different and that's what art students need. They're usually more nervous than you are." On a personal note, I wonder how he deals with the issue of a shrinking violet, to use a euphemism, particularly in those draughty studios. "If it's cold, it can be a problem," he says, "but you're usually more worried about the opposite effect."

His words flood back as I step out from behind the screen. There is no laughter, no applause, just vertigo. A woman looks up, sharpens her HB pencil; a bearded man rifles through his bag and pulls out a crayon. We have a brief discussion about the poses they would like me to hold.

My instinct at this stage is to put my hands in my pockets. Instead, I fold my arms, unfold them. I am standing on a white sheet in optimum glory, flooded with light from the overhead windows.

For the next three hours this will be home. The session begins with 10 one-minute poses. "Just do something natural," says one of the artists. She pulls an example stance, like a teapot.Even dressed, it would look camp and I decline. "How's this?" I say, thinking John Wayne, without the rifle, at the door of an invisible saloon. They nod, someone coughs, and we begin.

Mentally, I am primed. For those new to public presentations, business gurus sometimes suggest imagining that your audience is naked, therefore giving you the illusion of power. With the tables turned, I imagine myself in a boiler suit, heavy boots, a welding mask.

My first proper pose is a poor man's version of the lotus position, all legs, shoulders and arms. I focus on a crack in the wall and visualise myself climbing into it. In my peripheral vision, I can see the artists sizing me up with thumbs against pencils, re-sharpening points. There is no talking, no request for me to move. In a way, I suppose, it's quite easy. For some life models, the profession can be more demanding.

Postgraduate student Rosemary James from Galashiels occasionally gets tricky assignments. Like others I speak to, she entered modelling through word of mouth and has no artistic background. She enjoys being part of the creative process. "An artist covered me in plaster once, and I had straws sticking out of my nose. Three days later, I was still picking material from my arms and hair." She has never had an issue with being naked in front of people but insists she is no exhibitionist.

Quietly spoken, even timid, it's hard to imagine her streaking across a rugby pitch, or taking walks with the naked rambler. One advantage of having poor eyesight, she says, is being able to remove her glasses: with the room a shapeless blur, she feels cocooned, an artistic butterfly in waiting. When motion is involved, things are less straightforward. "One time, they had me running around the room, jumping up and down for ages," she says. "It felt quite strange, quite intimidating, but they were trying to get the muscle structure in my legs."

Both she and her boyfriend like to see the finished product of her labours. Seeing how others interpret her body can be more revealing than a mirror, James says; being at the centre of the artwork is often better than visiting a gallery. "It's narcissistic in a way but a drawing tells you more than a photograph. Artists take pleasure in the flaws, in the little odd parts about your body, and that just makes you appreciate them more."

One thing buzzing through my mind today - along with the song Let It All Hang Out, and the fear the artists are just drawing stick figures of my body - is the hope that I too will be transformed by this experience. At the first break, after 28 stationery minutes, I am told to get dressed for a while, if I want to. I want to.

By this point, I have nothing left to hide, but I shuffle sideways to the safety of a prop box. My trousers are inside out, much as they would be on my bedroom floor. The blue modesty screen in the corner beckons like a friend. It hits home that the dressing and undressing stage isn't easy: somehow, it marks the difference between being naked – which I suddenly am – and nude, which I was until a few seconds ago. Apparently, my concerns are shared by others.

"Most life models find dressing and undressing really problematic," says Sarah R Phillips, author of the book Modelling Life, for which she interviewed a plethora of life models. "Undressing in our culture is seen as a sexual thing and conjures images of a striptease. It creates certain problems that being nude doesn't create, which is funny."

From my vantage point on the studio floor, the fun is lost on me. I have to approach my zips with caution; my T-shirt gets stuck on my head. But at close quarters,I can sense a genuinely friendly atmosphere, a workaday feel to the whole endeavour. Which could also be true of bordellos.

*Les Demoiselles d'Avignon. 1907. Wikimedia Commons.*

Picasso's groundbreaking work, Les Demoiselles d'Avignon, caused a stir in 1907 as much for its depiction of French prostitutes as its explosive Cubist style. Here was a deliberate subversion of the idealised nude made famous by the ancient Greeks, who liked their heroes and heroines to be flawless.

The Demoiselles, by contrast, straddled the gap between intellect and sexual desire, bridging tat and titillation with ease. In the preceding centuries, nude portraiture in the West had been used typically, if at all, as a metaphor for religious purity or shame. The 16th century masters began reinterpreting the genre by looking back to the impossible Greek ideal.

Not until the rise of photography did the nude – stripped of the need for lengthy modelling sessions or aesthetic perfection – really prosper. Every day bodies were displayed on gallery walls and dirty postcards simultaneously, providing fuel for a moral meltdown. Today, the argument is still heated, if only because nudity remains, for the most part, a social taboo. There is no code of conduct governing the relationship between artist and model. It is a question of mutual respect.

"Obviously, if you're an artist drawing a naked body you have to look at the genitalia, which goes against how we are trained to use our eyes," says Phillips. "And so we have certain questions. How long can you look at a model's penis before you cross the line and it becomes sexual?"

It sounds like a joke, with no punchline. Phillips thinks the answer is one of degree. "Most models I spoke to admitted it's sometimes sexually arousing for both the artist and model during a pose," says Phillips. "That was generally fine with the models as long as it produced decent artwork. But if arousal becomes the end rather than the means, that's no longer acceptable."

Thankfully, that issue seems irrelevant today. For my second break, the artists invite me to see their work in progress. The first impression is of a standard human body. There are arms, legs, a head. It's a me I can recognise in different ways on different easels.

As a group, the artists discuss prosaic technical details: the distance between my nose and mouth, the line of my back, the curve of my belly. One artist rubs frantically at my arm, or the representation of it, while munching an apple. It's a pain to draw hands and wrists accurately, I am told: it's best to leave those till last. Temporarily clothed, I feel neither talkative nor quiet. I am removed, at least inspirit, from the process, until I return to my Biblical state.

"The human body is something we can all relate to in a completely intuitive way," says Martin Hammer, co-curator of the SNPG's forthcoming Naked Portrait exhibition. The show will unveil nudes, in all their forms, as a window on the last 100 years. There will be body parts by Egon Schiele and Robert Mapplethorpe; hips and breastbones by Lucian Freud and Annie Leibovitz; contemporary skin-jobs by Tracey Emin and David Bailey.

"In some of the earlier material there's an undertone of anguish and anxiety," says Hammer, "with nakedness expressing the artist's alienation from society." Increasingly, he says, female and gay artists have become famous for reinterpreting the nude portrait, ensuring its continuity and diversity. "In all of the works, there is a sense of human vulnerability," he says.

"When we shed the outer façade of how we want ourselves to be seen, there is a universal sense of mortality and the pathos of the human condition."

In quotidian terms, those grand metaphysical concerns are replaced with the more mundane. Calum Proctor – head life model at the Glasgow School of Art (GSA) – complains about nagging aches, of painfully stiffened joints after a particularly demanding session.One of only two salaried life models in Scotland, he puts tutors and life models in touch, in addition to his own modelling duties.

The impetus behind his career was a magazine article in which Franz Ferdinand drummer Paul Thomson discussed his time as a life model at the GSA. Proctor arrived at the school shortly afterwards, armed with a first-class degree in English and Russian. Tall and sinewy, he has his physical work cut out.

"You can't martyr yourself but you can't insist all the poses are brilliantly comfortable," Proctor says. Compared to his previous jobs, which were retail-based and unfulfilling, he thinks he's on to a winner. Even when it hurts. "Unfortunately, if you have a physique like mine, it's best suited to twisty, anatomical-style poses rather than something Rubenesque."

Though the life modelling scene is not hugely competitive, Proctor says the GSA is over-subscribed with would-be models. Some will be going through a phase, he predicts; others are around for the long haul. He got his own break at the school despite arriving late for his first class, and the fact the artists are wary of first-timers. "It's slightly problematic because everyone's got to have a first time," he says. "But the artists know things are scuppered if a model doesn't turn up."

Proctor's modelling colleagues include a professional cellist and a struggling playwright. He would like to work in advertising but is happy with life at the moment. He works limited hours, which is a bonus, and the modelling gives him time to reflect. "I'm trying to add to my scanty knowledge of European history at the moment, so while I'm posing I'll run over the key facts and figures in my head. I begin with the main people and places and just take it in order from there."

Bodybuilder types are generally not suited to life modelling, precisely because their bodies have been built, Proctor says. But otherwise the door is open. Part of his role is to find new models, of any shape or age, as long as they don't all look the same. Clothing, of course, is not needed, although a layer of thick skin is a must.

"When friends introduce me to people my job usually comes up very quickly," he says. "It's funny seeing my nudity paraded as this big deal wherever I go. The artists see you differently – for them you're like a more interesting bowl of fruit."

For some, the impersonality of it all can grate. Most life models see themselves as collaborators who are inseparable from the finished product. Yet few are ever credited by name. Gala – the wife and muse of Salvador Dali – is one of the few well-known exceptions. The nude might be discussed, pored over, admired, but rarely in relation to the sitter.

Instead, the artist and their craft take the kudos. It doesn't necessarily deter volunteers. Thousands have gathered in cities worldwide to participate in the mass nude photography of American artist Spencer Tunick. Wrapped around landmarks, dustbins and each other, they receive a signed photographastheironlyreward.But regardless of their anonymity, there are those who approach life modelling with verve.

"You can contribute to the process by giving off a certain vibe," says life model Ingrida Dzonsone. At 21, her CV includes stints as a magazine model in Latvia, and a spot of professional dancing. She took up life modelling only latterly, when she came to Scotland to study.

Her first session was uneventful: with only an hour between the phone call and the dressing gown, there was no time to get seriously nervous. Blonde and ambitious, she takes the topic of nudity in her stride. "Because of my background, I often do dance-like poses, so modelling is almost like performing for me," Dzonsone says. "I always try to inspire the artists, to be their muse."

A by-product of the job is that she now feels more comfortable in her skin."Fashion photography is all about vanity - a certain amount of make-up or a certain amount of weight to lose. Being naked is something you can't mess with, unless you do something drastic like surgery."

Her father, Dzonsone says, is happy with her choice, but he mother is more reserved. Though essentially a student job, with a slightly different skill-set of flipping burgers, she plans to continue life modelling in the future. While not ashamed, she is selective about who she tells. "Your body and how it looks is a piece of information about yourself and people can be very wary of that.

Life modelling is the most honest you can be because you're raw. You learn so much. Every girl wonders if she's getting fat but with this you see yourself in terms of shapes and lines."

For all that, there are fewer life drawing classes than there once were. Novel ideas such as Dr Sketchy's burlesque life-drawing sessions have been a success in venues acrossScotland. With live music, well-stocked bars and "outrageous" burlesque dancers, the events promise to set creative juices flowing. In an age of conceptual art and liberal attitudes, it's as if the stripped-down body is becoming old hat.

To give fresh impetus, Edinburgh-based artist Damian Callan will lead a series of life-drawing sessions, complete with materials, tying in with the Naked Portrait, aimed at adults and Higher students. It is, he admits, a labour of love. "If you paint a mountain and it's not quite like the mountain, you can get away with it," Callan says. "With a body everybody knows if it's wrong. It's fine to paint lemons and limes but humans offer far greater possibilities."

Though life drawing is losing ground in many mainstream colleges, he says, there will always be people who love its curving lines.

In my own case, those lines are beginning to sag. I've been labouring under the illusion that I will avoid the worst stresses and strains of the profession. But with half an hour to go, the artists want me to experience the authentic pain of holding an unrealistic position. "Try this," says one.

He gets onto the floor and imitates a rower at full stretch, his body steering out from the boat. "Yes," I say, "I used to row." But, without the Lycra, it's not going to happen. The pose we agree on – I'm on my knees, my body weight resting on folded toes – is a bad choice.

A friend who studies Vedic meditation has talked to me at length about the ability to ignore pain. I'm trying to put this into practice. It's not easy. I begin counting toes off consecutively as they die on the vine. My watch is on the floor but I ignore it: if I can survive the seconds, I think, the minutes will take care of themselves. As my knees begin to buckle, I am in a space not of this world or any other.

By the time both arms are dead my body is shaking perceptibly. I need some eternal wisdom, I think. Staying upright is becoming unbearable and no-one is throwing the towel.

"I haven't toppled over yet but it could happen," says 68-year-old Gordon Robertson. If he can do it, so can I, I think. Robertson is at peace with his clothes on or off, but definitely prefers the latter. An ex-British Rail employee, he has been a fully fledged naturist since 1999, and regularly plays boules in the buff. He was jaunting along a nudist beach in Brighton a few years back when someone suggested he become a model, to his laughter.

"I think it's flattering that anyone would want to draw or paint me at my age," he says. "I'm fairly slim, but I'm no spring chicken." He enjoys his job, and the impassioned conversations about art, even though "all I can draw is breath". His friends would be shocked, he says, that he is a model. Not because of the nudity, which he parades like a badge of honour, but because he has never been one to sit still. "For me, it's worthwhile because I'm helping people in their studies. If I can do that as I pass along, then perfect."

As his words trail off in my memory, I can see a slow waving hand. "You can get up now and stretch your legs," someone says. It's an assumption, rather than a fact. Wherever my blood is, it's not in my legs, and won't be for several minutes. By the time I am finally dressed, the artists have gathered their things together.

They no longer look like artists; and I am back from the world of lines. We exchange numbers, a little embarrassed, and say goodbye.

First published in the Sunday Herald.

Paul Dalgarno

Paul Dalgarno

Features

Paul Dalgarno

Life drawing – with some skin in the game