Christie's uncovered: Anatomy of an auction

we all know how an auction ends – with a crash of gavel, a depleted wallet and a dented ego or two – but how do they begin? Christie's auction room in London's St James's has seen more action than most. It has been in use since 1823 and the blockbuster Impressionist and Modern Art evening sale on Wednesday will be one of its busiest of the year. Dealers and collectors from all around the world will be donning their smartest suits and gathering to bid on landmark paintings by Monet, Picasso and Degas, spending millions during a frantic and dramatic evening. But this is merely the public climax to a project that is three months in the making. Long before a painting reaches the rostrum, it has to be sourced by Christie's multinational team headed by Giovanna Bertazzoni and Olivier Camu, and its owners persuaded to sell. Potential buyers across the globe are alerted. Paintings are restored, reframed, studied and valued. And throughout, the team must balance their visceral love of the art and the calculating demands of the market.

Bertazzoni, Christie's head of Impressionist and Modern Art, is a slight Italian with a passion for competition honed in teenage gymnastic competition. "The auction k is incredibly stressful," she says. "It's fascinating but it's draining. It's the culmination of everything. Every time the hammer comes down you think about the conversations you will have with people who are happy and people who are not. Every sale has implications. Last time I forgot to eat all day and fainted. But it's exciting. When you've pulled in a work and believe in it and other people like it and the seller is happy, that's amazing."

We meet at "hilling", Christie's jargon for the sessions at which paintings are painstakingly examined. One day early in December, Bertazzoni and two colleagues have gathered in a Christie's warehouse, uphill from, but connected to, the main building (hence, "hilling") to study two paintings for February's sale – a £1.5m Camille Pissarro watercolour (Vue de ma fenêtre, inondation, effet de soir, Eragny, 1893) and a pastel by Edgar Degas valued at up to £5m (Danseuses jupes jaunes, c1896, pictured on page 23). There are 46 lots in all, plus a further 32 for the evening's Art of the Surreal sale. Together, they have an estimate of £109m – the second-highest pre-sale February estimate at Christie's after 2008's £125m. Last year's sale, by contrast, was estimated at a maximum of £81m, and actually took £66.7m – although rival Sotheby's corresponding February Impressionist sale of £146m, a London record, showed the market's overall strength.

These numbers are what it's all about, and they are why hilling is taken seriously. Bertazzoni spends an hour looking for blemishes and deciphering yellowing labels on the back of frames to determine provenance. "Hilling is un-glamorous and full of jargon. It's the nerdy part of the job," she says. "It is the moment the works arrive in London and we assess them. We make sure we are happy with the estimate and check whether there is anything we need to speak to the owners about."

The Degas, Bertazzoni believes, will be a major lot. "It's a pastel and charcoal on joined paper, signed and with a simple line of provenance. It's what the market wants – flashy, iconic, unique, his high subject. It'll create an interesting competition."

Christie's acquired the picture from a European collector who "wanted to tidy up some affairs. So we went to her home and inspected the asset. Then we went through the proposal, gave her financial advice, she thought about it and agreed to co-sign."

Persuading vendors to sell through Christie's is a key part of Bertazzoni's job. "It is very intense. You have a presentation and you talk through the financial implictions. A year ago we were pitching and I promised that I would cartwheel through the department if we won. And I did!" (The commission structure is complex, but Christie's can take a payment from both the vendor and the buyer.)

Bertazzoni's boss, Camu, a Belgian-born 47-year-old with a banking background, spends much of his time meeting vendors. "There are all sorts of situations," he says. "Sometimes people say, 'We want you', sometimes they say, 'We want you, but we want this estimate', sometimes they'll say, 'You're coming at 11.30am and Sotheby's is coming at 11.45am and you can see the picture for five minutes in a vault.'"

The flow of the market is particularly revealing. "Our product – paintings and statues – is [currently owned by] old European and American families," explains Bertazzoni. "There comes a time when they have to decide whether to pass the collection to the next generation or to sell it. Sometimes they will be updating their collection, replacing Impressionism with post-war work. So Impressionist paintings are being sold, which is great for us, because that's what the growth markets in Russia, Asia and the Middle East are looking for. Culturally, it's fascinating."

The art market has remained surprisingly robust since the 2008 recession. "The market has been much sounder that we thought it might be," says Bertazzoni. "But we had a lack of supply. Our sources were largely untouched by the crisis but they didn't think it was a good time to sell. Now the volume is back, but it's not as undiscerning as it was before 2008." Bertazzoni notes that the crash led to a demand for sculpture. "It's as though people wanted something tangible, three-dimensional." At Sotheby's in 2010, a Giacometti sculpture sold for £65m.

Camu, who sold a record-breaking £41m Monet in the pre-crash June 2008 sale, concurs. "It was a major contraction: we went from 100 lots to 30. But now it's saner. People listen. In 2008, there were too many unsold lots and now we sell more lots while reaching the same prices because estimates are more sensible."

Prices have been sustained by a new breed of collector. Jussi Pylkkanen, president of Christie's in Europe, says, "The market used to be cyclical, but now it's more stable because of the engagement of a vast group of buyers who were not involved a decade ago: Russians, Chinese buyers and a new generation of Middle Eastern and Arab clients. Also we've seen the Medici-style collector appear, the great wealthy international collector who will buy the best of every field."

This international clientele means Christie's is a cosmopolitan and youthful place despite its location in stuffy London clubland. Camu, Bertazzoni and Pylkkanen all speak at least three languages – Pylkkanen was born in Finland but educated in England – and all are in their forties. The auction house operates in a world where discretion – no client is mentioned by name – goes hand-in-hand with headline-grabbing prices, but they are keen for the public to brave the uniformed doormen and intimidating façade. All lots are on public display at their gallery, including Picassos, a Monet and a Gauguin valued at up to £10m.

Look, but don't bid: this remains the privilege of the über-wealthy, and the auction is a ticketed event with seats reserved for registered buyers. "If anybody intends to bid, they must lodge an interest and we will politely ask for the name of their bank," says Camu. The following afternoon's Impressionist and Modern Art day sale is, like most Christie's auctions, open to anybody.

In January comes the moment of revelation. The catalogue is sent to 6,000 key clients revealing for the first time the lots and their estimates. From now, the sale is reviewed each day as specialists try to discern who will bid on what. Previous unsuccessful bidders are contacted and their interest tested. All information goes to the auctioneer, who choreographs the sale, managing bids on the phone and written pre-bids alongside the action in the room. "The auction is the major event," says Camu. "We have to make sure we position people in the right place and do lots of little things to keep it smooth."

The auction itself passes in a flash. "An evening sale is very exciting at the beginning," says Bertazzoni. "But after about an hour the make-up is starting to run, the dinner reservation is waiting, the hammer isn't coming down quite as sharply... it has to be quick."

And when the victor walks off with the spoils, does Bertazzoni, who trained as a curator in Paris and San Francisco, ever mind that a historic work of art will stay in private hands? "Art can still change people and if you chose to spend on a Monet rather than a yacht, then I respect you. Even the most callous investor, one who is here just to find something to put in a warehouse, has a spark, the moment when they realise they do it because they love it. They probably never in their daily life have another instant when they consider an asset because it is beautiful."

Christie's: The inside stories

Giovanna Bertazzoni 43

Head of Impressionist and Modern Art

"I was a curator but got a job at Christie's and have been here for 13 years. I began as editor of the catalogue. English is my third language so it was a struggle, but it taught me how to be quick and efficient. My job now is to manage the evening sale. I co-ordinate the business-getting strategies of six senior people in Europe and America before sales in February, June and November. We set targets then work on getting the buyers in the room. We have great data. By the time we start, we have a pretty good sense of who will be bidding, but there is a lot of testosterone-buying. It's about ego. When you buy, it can be very Freudian, proving yourself sexually, for men and women. I'm too hampered by my Catholic upbringing to spend a lot of money and feel good about it, but my clients lost that long ago or never had it at all."

Gino Franchi 47

Restorer, framer and mounter

"I've been doing it for about 25 years. You'll be surprised, but some works of art that are worth an awful lot of money are really badly framed or in poor condition. Giovanna and I will decide if I can re-present them; I've done about 12 for this sale. Most of my frames are antiques, often acquired in auctions, but I will make frames for contemporary art. I cut them to size and repair them. I also hand-paint the mounts – the card that goes around the k border of the painting – to give it movement and texture, and I change the glass. I work with the painting in front of me because without the artwork, it's virtually impossible to get the right effect. You have to match the frame and the mount to bring the depth and colour out of the painting, to make it look stronger. I love art, and always have, and am lucky enough to have an eye that allows me to enhance it. Hopefully, I help people see paintings as the artist intended."

Rob Brown & William Paton 47 & 35

Catalogue researchers

RB: "We write catalogues for evening sales. These are not dry reference works, they are more in-depth than a standard coffee-table book. We explain what you are buying into, what the artist was trying to do, where it fits into their life and into art history."

WP: "We do about 10 a year, and we also do one-off catalogues for individual paintings. The specialist ones go to the top 1,000 clients. The normal ones go to around 6,000."

RB: "Sometimes we get a few weeks to write a piece, other times we get 20 minutes. It depends when the work is acquired. We write about 1,000 words a day. Entries can be anything from two paragraphs to six pages."

WP: "We're very lucky. I've had Van Goghs that I can sit and look at while I'm typing away. We can interact with the paintings, see the history on the back. It's an incredibly privileged position to be in."

RB: "We go to the sales, because there will always be a few lots that we strangely care about. For me, it doesn't matter what price they get, but I'm happy when there's a work I've liked and you see it going to what you think is a good home."

Will Fergie 37

Art handler

"I've worked here since 2003. Whatever happens to the pictures, wherever they go, I'm involved. I take them to hilling, to restorers, to viewings and to sales. I try to keep them inside the frames and behind glass as much as possible, especially with pastels and works on papers, so that means we are taking them in and out of frames quite a lot. I have a Masters in History of Art, and it makes it more interesting. On quieter moments I can choose what pictures to put on the wall of my office at the warehouse, maybe a Matisse or a Picasso. At the moment there's a little Pissarro up there."

Jussi Pylkkanen 47

Auctioneer and European president

"I've been an auctioneer since 1995 but I'm also European president of Christie's, so I have a good idea of the prospective bidders across all markets. You have to manage the room, the bids in the books, the bidders on the telephone communicating in different languages, but the key thing is to manage the pace of the auction. You're fully engaged for an hour and it's exhausting. You don't know until you get on the rostrum if you are up to it – it's a skill and you've either got it or you haven't. It's quite a lonely place up there. Nobody speaks to you, they're all just signalling, but you develop a sense for faces and body language. You are able to look into a sea of 600 people and immediately identify the two or three people who will open the bidding. You only have 60 seconds to sell each lot, but that 60 seconds is vital to the buyer."

Viewings at Christie's, King Street, London SW1, from midday until Wednesday; christies.com