IT takes Philip Castle up to three months to complete one of his huge cityscape canvases, so full of detail are they. His wife, the painter Barry Castle, works a lot more quickly because she paints what most people would regard as "normal" sized pictures.

"We always show together because Philip's are so big and take so long to do, he never has enough," Barry explains. Work together - or rather separately but towards the same end - they can get an exhibition together in two years. And the fruit of their last two years work goes on show at London's prestigious Portal Gallery in Grafton Street (off Bond Street) this evening, when the Irish Ambassador to Britain, Mr Ted Barrington, opens their latest exhibition. Philip has four in the exhibition, Barry fifteen.

Barry - daughter of novelist, and cookery writer and journalist Maura Laverty and Irish Times journalist James Laverty - met Philip Castle, a Londoner, when he was at TCD, studying physics under Ernest Walton, the Nobel Laureate. "He dropped out, never had any formal art training. He taught himself and then he taught me - even though I had been to art school." Indeed, Barry had gone to the College of Art, where contemporaries were Pauline Bewick and the RHA president - Tom Ryan, at the tender age of 15 "because I wouldn't go to school".

Sins Of Omission

"I was thrown out because they thought I would never make my living at it. We used to sit on hot pipes, talking about fellas all day. My sins were of omission rather than commission, I was so timid."

With a career as a painter apparently off the horizon, she married Philip and they went to live in Villefranche in the south of France in the mid 60s. "I use Philip's techniques when I paint. I learned by watching him. Philip has a technique of putting on paint so it looks like stained glass. It's transparent, the light shines through it, it's delicate. He uses bright colours and a fine finish."

But he paints cities and buildings, while she paints people and animals. A recent canvas of his was of the Irish Financial Services Centre, which shows the quantum leap from the old idea of money and the concrete value of money to the insubstantial glass tower blocks of the new money era. His works range from very detailed cityscapes, often very modern, much of which he admires, to Mediterranean cities. Meanwhile, Barry paints delicate, light, swirly, foliate people, domestic fowl, fish and animals. "Increasingly I'm painting wild animals instead of pussy cats. I think as you get older, you get wilder," the author and illustrator of Cooking for Cats muses.

For this exhibition, they have combined on a huge painting of Helen of Troy. "He did Troy and I did Helen. We may never do it again, but it's a complete picture and doesn't look like a mixture." She's also done a Madonna and Child, detailing the Flight into Egypt.

Philip has been showing at the Portal Gallery for 25 years, Barry since 1974. On alternate years, they have exhibitions in Dublin and New York. Barry's paintings tend to be in the £500 to £5,000 bracket, while Philip's sell for around £8,000. Seems hefty, perhaps, but considering the fantastic detail and light - and the three months they demand - it's not bad.

Afternoon Siesta

Barry works from around 4.30 a.m., when she wakes, until breakfast and the other interruptions of the day. "Then I often take a siesta. Philip gets up at the normal breakfast time and works until lunch. Sometimes we both take a siesta in the afternoon. It's essential to have a lot of wine or you don't sleep. Then we start work again. That way we feel we get two days work into one," she laughs, before lamenting that she "couldn't afford that lifestyle in Ireland.

Their main base continues to be France, but many years ago they bought a small derelict farm in the north of Italy "because Philip thought the Dark Ages were coming and we should have a farm and feed ourselves. It was derelict, a real rural slum. Still is, but we live in the pig sty, which has been improved." Slum it may be, but it provides them with two months of peace when the French hordes descend on the Mediterranean and it's impossible to work day or night.

Untimely Death

It was in Italy that Barry kept all her mother's papers, after her untimely death at the age of 58 - when she had just achieved monetary as well as - literary security with the success of RTE's first "soap", Tolka Raw. "I kept all her writing in tin boxes just as well, the rodents would have devoured them. When the National Library wanted to acquire her stuff, I went through them again and started reading the fairy stories: They, took me right back to holidays in the west of Ireland. And even though I was in Tuscany in the summer, I started to do water colours for the stories." The result was The Queer of Aran's Daughter, a beautiful book of illustrated new Irish fairy tales, published, last year in Ireland by Poolbeg and to be launched in London on Wednesday.