These days technology has forced even prostitutes to innovate as Dutch prostitute Terry van der Zijden proudly points to a photo she took of the bedroom in which she plies her trade; a sexless still-life neatly mounted on the wall of an Amsterdam art gallery.
"There is my bed, that is my bureau," she states matter-of-factly in front of a picture of a room with tranquil green linen, scatter cushions and potted flowers -- part of an exhibition entitled "This is my workplace" by sex workers who completed a photography course in June.
Van der Zijden works at home in the south Netherlands.
"It is a multi-functional space. It is suitable for having sex, but it is also where I sleep," explained the 65-year-old in a chaste skirt suit and red, high-heeled, leather boots.
Van der Zijden, whose pictures seem tame among those of dildos and studded leather restraints taken by some of her colleagues, said she hoped the exhibition will challenge people's prejudices.
"When people think about prostitutes, or whores as some call us, they have a certain image in their heads. I wanted to show that a sex worker can be making her living behind any arbitrary door," she said, pointing to another photo of her living room with a Humphrey Bogart poster on the wall, book shelves and a computer.
"Prostitutes are not just women who lie on their backs. We can also be photographers. We also have other interests."
Ex-prostitute and labour unionist Metje Blaak, 61, said the course she presented was paid from a government empowerment grant.
Twenty women took part, aged 20 to 65 from around the country, of whom 12 are exhibiting at the small Vriend van Bavink gallery around the corner from Amsterdam's famous red light district.
"Part of our aim was to help the women realise 'I can do more than that'," said Blaak, referring to sex work. "We want to give them confidence.
"Our goal is not to encourage women to leave the trade. But we want them to learn new skills so that they can leave if they want to."
Blaak, who quit the sex trade after 25 years in 1995 to become a professional photographer, said many women find it difficult to leave.
They have trouble putting aside a nest egg, often had few marketable skills, and lived in a cocoon they found hard to break free from.
"I myself was very afraid of the big, bad world," Blaak recalls of the time she decided to quit.
Blaak said the women reacted enthusiastically to the idea of learning photography, eagerly soaking up the finer skills of portraiture, composition and lighting during one-to-two hour, weekly classes presented over a month.
"At the end, I gave them an assignment to photograph their work rooms. The results were so good that we decided to put on an exhibition," she said.
The result was 50 pictures that provide a revealing look behind the scenes: men trawling the streets for sex, a whimsical lipstick smear on a coffee cup, and ironic depictions of multi-coloured dildos, lingerie, whips and chains.
Brothel owner Willy van der Sloot, 57, halts at a picture she shot inside the room of one of her tenants.
"Those clothes pegs are for clamping nipples," she points and explains, giggling playfully.
Van der Sloot believes it is good that people "get a glimpse behind the curtains".
"I know how curious people are. It is nice that they see what is inside, that they can get an idea of what happens there, to understand better."
Though the world's oldest profession was long tolerated in the Netherlands, it was only legalised in 2000.
According to Blaak's De Rode Draad (The Red Thread) labour union, there are about 25,000 sex workers in the Netherlands, working the streets, behind windows, in nightclubs, brothels, private homes, massage parlours and escort agencies.
Gallery owner Ruben Bunder said the opening of the exhibition was "one of my biggest ever" in five years, explaining that "sex always attracts clients".
A dozen of the photographs have been sold for up to 400 euros (about 550 dollars) each, the proceeds of which will go back to De Rode Draad for future projects.
Hundreds of people have seen the exhibition since it opened on November 3, said Bunder.
"Due to popular demand, we have decided to extend the exhibition by a week, to December 3."