Illustrator Quentin Blake likens himself to a theatre producer, bringing characters to life. For 40 years his work has captured children's imaginations.

Today he feels touched by the way in which his first young readers, now grown up, bring their own children to book signings.

He is best known for his Roald Dahl creations and does not mind this association.

Mr Blake, who is 70 in December, said: "For me, drawing is a kind of celebration. I am rather like a theatre producer imagining what people look like, what they are doing and what the scenery is like.

"I don't mind at all that I am so associated with Roald Dahl. He is a big part of my life."

He first met Mr Dahl when he was asked to do some sample drawings for the Enormous Crocodile in 1975.

He went to visit the writer at Gypsy House in Great Missenden. It was here Mr Dahl recounted his made-up stories to his children which inspired him to become an author.

He used an old shed, full of cobwebs, in his back garden to write his fantastical tales.

Mr Blake said: "We had a very good professional relationship which got stronger as time went by.

"He was very concerned that we should get the best effect for the book. Sometimes he would ask me to change my drawings and sometimes he would change his words to fit in with my pictures. It was a real collaboration in that sense."

Characters which the pair helped mould in young minds included Matilda, The Twits, The Witches, Danny The Champion Of The World and Fantastic Mr Fox.

When asked which was his favourite, Mr Blake said: "Now that is a difficult question," and pondered for a moment.

All sorts of loveable characters could have been his choice. But, "It has to be the BFG," he said warmly.

In the book, eight-year-old Sophie is kidsnatched from an orphanage by the BFG (Big Friendly Giant) and taken to Giantland.

Luckily for her, the BFG is nothing like the other giants, whose favourite pastime is guzzling little children. Instead the gentle giant spends his days blowing happy dreams to children. He uses a jumbled language and is loved by many for his kindness.

Mr Blake said: "The scale of him was very interesting to draw because he is so tall. And I liked drawing his big ears.

"The images for the book took quite a long time so I got to know the BFG quite well. I liked the nature of his relationship with the little girl."

He said he liked the sense of mischief and caricature in Mr Dahl's books.

The author died in November 1990, aged 75, but Mr Blake continues to illustrate his books.

What many people do not realise is Mr Blake has also illustrated many other books. In fact, he did his first children's illustration 15 years before he met Roald Dahl.

Born in 1932 in Kent, the young Quentin had a quiet childhood and drew from a young age.

His first drawing was published in Punch when he was 16. His first book, Patrick, was published in 1968. He was awarded the Children's Book Award for Mister Magnolia, the story of a man with only one boot, in 1981.

He has also earned recognition in his own right with books such as the picture book Clown.

Green Ship is about a ship made from trees and bushes which takes two children to places all over the world.

Other authors for whom he has illustrated books include John Yeoman and Russell Hoban.

Mr Blake said all his drawings, which he likens to a kind of handwriting, are inspired by the manuscripts and the way characters react to each other.

He does not spend hours drawing from life but rather tries to capture a particular gesture or trait of a character.

On the humour in his drawings, Mr Blake said: "I don't consciously put humour into my drawings. It just gets in there itself. I don't try too hard to be funny.

"It's more to do with the way people stand, walk and act."

Much of his inspiration comes from his time spent at his 500-year-old hideaway in Hastings, which he has had for the last 25 years.

Here he sits and scribbles new characters in a room on the first floor overlooking the street. When he first bought the house it was in a state of disrepair but today it has been lovingly restored. An open fireplace and old timbers provide homely surroundings.

He said Hastings' cliffs, landscapes and sea, which he loves so much, often creep into his illustrations.

Blake said: "Hastings is full of fascination. It has all human life.

"It is very quiet in the winter and I love walking along the cliffs and buying fish on the seafront. I feel very at home."

He also spends time at his house in the south of France and at a flat in London.

While many people his age are enjoying a quiet retirement, Mr Blake is still very busy.

The mild-mannered artist said: "I would feel bad-tempered if I couldn't draw. The most I can go without drawing is two weeks. That is why I have a house in France so I can believe that I am on holiday but still draw."

When asked which characteristics of himself get into his drawings, he chuckled.

"A kind of hopefulness or cheerfulness which is appreciated by young readers.

"I suppose I am quite a positive person which rather surprises me sometimes."

It is this sense of optimism which inspires others. He was made Children's Laureate for two years in 1999.

He has just written a book about this experience, called Laureate's Progress.

For Mr Blake, who studied English literature at Cambridge with the intention of becoming an English teacher, education is important.

That is why he, along with artists including Gerald Scarfe, Posy Simmonds, and Steve Bell, agreed to spearhead the Big Draw, which kicks off today.

Organised by the Campaign for Drawing, the event aims to get as many people as possible drawing during a week of events across Sussex and the rest of the country.

Artists, cartoonists, architects and illustrators are leading activities for young and old, beginners and experts.

Mr Blake said: "I started drawing when I was very small, kept going and have made a living from it.

"But lots of children get inhibited by drawing and give up. But you must do a lot of drawing until you become familiar with it.

"The popularity of my drawings constantly takes me by surprise. It is very nice to be appreciated."

His latest picture book, Loveykins, is about a girl who discovers a baby bird after a storm. She feeds and nurtures him until one day he flies away.

Loveykins and Laureate's Progress, both published by Jonathan Cape, are out now.