All The Young Nudes in Edinburgh now has more than 300 people of all shapes and sizes willing to bare all to make some cash.
Joanna Susskind, the class organiser, said the number of models has doubled since this time last year when she was in contact with 150 people.
She said: "I have a book with about 300 names in it, and every week more people get in touch to ask if they can have a go.
"It's great that there is so much enthusiasm but a lot of people admit they've never done nude posing before and I ask them to apply again once they have experience. Posing isn't as easy as it looks, and I need to make sure the models know what to do or it ruins things for the artists."
Joanna, 28, began the events at Glasgow bar The Flying Duck after taking part in classes herself at the city's School of Art.
For less than £5, artists can attend and turn their hand to a rich variety of subjects.
She added: "I have a staple group of about 20 different models of both genders, in all ages and sizes who we rotate so there's a brilliant mix of subjects.
"I really would encourage anyone who's ever wanted to give drawing or painting a try to come down.
One model who regularly features is 30-year-old Johanna Samuelson.
She has life-modelled for three years but admitted it took her a while to get used to posing for long periods.
She added: "It did take me about two years to build up regular work as most classes do just want experienced models, but now I pose for artists all the time.
"Even if you're just doing a short pose, anything that involves flexing your legs or feet will lead you to start shaking, very quickly."