When Dame Diana Rigg goes to the London fairs in June, she chooses her moments carefully, particularly at Grosvenor House. "Frankly you're jostling with terribly smart people," she says, "and I like to go there to look at the objects and not to look at the others."
In this, she is unusual. For most visitors, part of the fun of the fairs is eavesdropping on the conversations and guessing who all the other visitors are. Interior designers? Museum collectors? Dot-com millionaires? No darling, that was last year...
Dame Diana is an habitue of arts and antique fairs, big and small. "I've been going for years and years. The Olympia is a great favourite of mine."
She has watched interest in the fairs grow, probably, she thinks, thanks to the Antiques Road Show and the economy.
Impulse buying runs in the family. "My father never had much money, but he used to go potty once in a while and buy something which would make my mother tear her hair out, something which frankly she didn't want and he thought was absolutely wonderful. We had a whole Chinese tea service which just sat in a cupboard. The cupboard fell down eventually," says Dame Diana.
Her own collective instincts were aroused when she was a drama student, lodging in Clapham. "There was a man with a little antiques shop there who talked about the Ming dysentery (sic). Of course, I couldn't afford anything. Then when I graduated to the Royal Shakespeare Company and we were at the Aldwych there used to be a wonderful little shop at the top of Drury Lane," she says.
"The gentleman who ran it was wonderfully scholarly and polite and if I timed it right, just before the shop shut, he would invite me in, pour me a glass of sherry and show me all his Roman jewellery in his safe. I loved it because he took out one bit after another and explained where he'd got it, where it came from, and so on. It was a wonderful way to pass the early evening before the half (half an hour before curtain up)."
When finally she had the money to buy, nothing would stop her. "I bought an old wooden statue, a caryatid, in Czechoslovakia and schlepped it around the world on an RSC tour. I still have it. I can remember the pleasure it gave me over the years and how it was wrapped in newspaper in my suitcase."
Was it a bargain? "No, the pleasure was finding something old, and absolutely falling in love with her big fat tummy and round cheeks, and loving it ever since," she says.
"The first piece of remotely antiquey jewellery I bought was at Stratford market - a silver ring with a jade stone. My daughter Rachael wears it now. I have nothing rare or expensive but I've got several small paintings of which I'm extremely fond. They started small because that's the only kind I could afford, and they stayed small.
"The only large painting I have was painted by Lester Sutcliffe. He was a scene painter at Leeds Grand Theatre, which was the theatre where I first saw a play and that's why I bought it. "
At the June fairs, Dame Diana is never afraid to ask the exhibitors about their wares. "They are divinely generous with their knowledge. I always say I'm not buying it but could you tell me about it? They just really enjoy imparting their enthusiasm," she says.
Does she trust the dealers? "I do. There's a saying that if you like it, the price is right and I think it's pointless going round saying that they're all on the make. I like to think they're in it for the love of it and not to make a huge profit at the expense of the public.
"I also buy at auction. I like the thrill of it. Some people have a natural eye. I don't think I have, but over the years it definitely develops.
"I've never bought anything from a production, but I've been tempted. All that stuff that you see in the back of Victorian or Elizabethan dramas are hired from vast warehouses that have the most remarkable things in them. I always talk to the set designers and I have a good look at everything on set.
"They put old books in the bookcases and some of those are very interesting. Similarly, if you have a scene where you are sitting in front of a desk, they've got these old letters and old diaries."
Late in the summer, Dame Diana opens in the play Humble Boy at the National, but for now she's taking French lessons. "I've bought a house in Gascony. I'm going to go there to buy French furniture."