Looking at the great nude portraits of the past – the Olympia, the unclothed lady picnicking next to the suits in Manet's Le Dejeuner sur l'Herbe – you can't help wondering what the models were thinking. Were they working out what to have for dinner as the artist got to work, or pondering the sort of deep or beautiful thoughts they hoped would look soulful on canvas?
Clare Broome is somebody who knows. She's a single mother in her 30s who lives with her 14-year-old son Robert in an apartment overlooking the River Lagan in Stranmillis in Belfast.
And she is also a life model who loves her work so much she has launched a business aimed at raising the status of the people who pose nude for artists here.
"What I'm thinking when I am posing depends, partly on how long the pose is. If I can't see a clock, I'll be reciting a rhyme or mantra to keep track of time. It's important to do that as artists who are concentrating on their work occasionally run over time and that can be very painful for me. If I'm not marking time, I'll be running through a film or book I've enjoyed recently."
Oddly enough Ms Broome, who has also modelled for hair magazines like Hair Now! and done some catwalk work, says she is more comfortable facing 20 students naked than a single photographer and lens fully clad.
"A friend said she noticed I wasn't totally easy with this modelling whereas I'm totally comfortable doing life modelling. That's true because I know what I'm doing. I am always happy in front of the canvas, it's my job. And I have always been easy in my own skin."
When Clare was at Down High School, Downpatrick, she didn't envisage a future as a well-known life model. She wanted to be a teacher instead, and went on to study Spanish at Queen's University, Belfast. "I don't have an art background and thought I'd live in Spain and probably teach English."
But two things happened during her four year course that propelled her in a different direction. The first was the birth of her son in her fourth year, after her study year in Spain.
She says now: "It was fantastic having my son while I was at university, partly because he's grown up seeing mummy study."
The second thing was that a friend of Clare's who had been a life model went into broadcasting and bequeathed her a client list. "I'd done some life modelling at university. When she asked if I wanted her list, I said yes as it was a job – and I found I enjoyed it."
It seems as if this transition was as smooth for Clare as becoming a mother, although her first job wasn't entirely incident-free. She recalls: "In my first ever session I was mostly concerned about not falling off this precarious chair on top of a rather wobbly table. And it was freezing in the old Crescent Arts Centre. The class was in a rather cold room, but I've trained myself since then to work at low temperatures so when required I can even work outside."
This outdoors work usually involves modelling in private gardens.
Since 2009, when Clare started her business, she has become even more passionate about life classes and nowadays she organises her own classes, which number 15-20 students, and collaborates with artists, supplying art equipment like easels and boards herself.
But what makes a good life model? There are physical requirements, although owning contemporary model proportions isn't one of them, as Clare indicates: "I'm six feet tall and a traditional shape, nice and curvy. In fact, I have to try not to lose too much weight, which is a nice position to be in. It's not the same as being a photographic model but it is important to be supple."
That is clear from Clare's description of some of the poses she has made up. For example, she does something called a Celtic knot. "The Celtic knot is a lovely wee pose but it's quite hard to explain. I get curled up on one side with my arms and legs intertwined. But all life models have their own style."
Attitude is also crucial when you're on the plinth or reclining on an artfully draped sheet.
"The model is vital to how the class goes and I think in my classes, the life model is as important as the tutor. After all, it's not a still life, there's a person not a bowl of fruit up there, so you have to respond to what the tutor's teaching.
"I'm aware of what poses look like and won't present a student with a really difficult foreshortening of my legs, for example, as that's hard to paint or draw."
Clare also makes sure to engage with the students and says she can tune in to the vibe of the class
When she first began work, the pay wasn't always great and models starting out earn around £10 an hour for a two-hour class. "A life class model's pay varies but because I run a business, providing equipment, materials and doing marketing, I charge a competitive rate. I work every day and have sometimes done a full day's modelling plus an evening class, which saves money on the gym. Very good models can command a bit more, but it isn't necessarily something you would go into for the money."
You might imagine the embarrassment factor could be a downside of this business, but that is not the case, according to Clare.
"Everyone has been really supportive. My parents have a nude drawing of me by Aisling McDermott.
"My dad made me some equipment and my son and nephew have helped out at costumed events, handing out leaflets and moving furniture."
Clare says that Robert is cool about her job: "My son knows what I do for a living and he's happy with it. But I'm aware that there are some pieces of art depicting me around the house that I need to put away when his friends come over."
Then she adds: "I think if anyone had an issue with what I do, they'd keep it to themselves or simply not hang out with me but everyone has been lovely."
But what about boyfriends' reaction to Clare's work? "I've never had a problem telling anybody what I do and by the time you've got to the point of going out on a date with someone, you have an idea of how the person will react."
She adds: "Of course, I realise the seaside postcard attitude exists, mostly because of embarrassment or lack of knowledge about life drawing. I'm happy to chat to people to dispel myths but I don't ever tolerate rudeness or someone making inappropriate remarks."
And crucially, there is a difference between being naked, unclothed in the shameful, Adam and Eve way, and being nude. Nudes inspire, act as muses and form an important part of the history of art. Clare says: "The way I'm looked at in class is impersonal. The students and artists are concentrating on trying to unravel the mystery and get the measurements right and in proportion. They're not thinking about me as a person."
Certainly, in any life class I've attended, references to the model's thigh or breast aren't suggestive, just factual. Clare says: "People ask 'Aren't you embarrassed?' but it's more likely that somebody coming to the class for the first time might be embarrassed. I try to help them overcome that."
Although life modelling has not been regarded as the sort of professional job – like teacher, solicitor, nurse – your careers teacher puts under your nose in the sixth form, Clare would like to change that. "It hasn't been seen as a professional career but I now train models and have a client base so if someone is unsure where to get a good model, I can recommend someone."
Clare is currently working on a variety of projects, some clothed.
She explains: "I model for animation classes and have to walk up and down stairs or do gestural poses to show the students different things about how the body moves.
"That's unclothed and I do expressions and feelings too, sticking my tongue out at the class. We also introduce fashion and I've done some fun sessions with hats."
Last summer, Clare went into partnership with artist Sharon Kelly to produce individual workshops. "We pooled our resources as we wanted to deliver life classes to libraries in areas like the Falls Road, Belfast, as well as places like Downpatrick that didn't have them."
Robert will not be following his mother into the arts. "No, he's science orientated and works as well. It's funny but my parents didn't really understand what I do until Bill Gatt, a painter I often work with, did a fully clothed portrait of them sitting together for Christmas.
"They said that even without sitting totally still, it was very exhausting."