THE BIG DRAW. October 20 and 21. Venues nationwide

Drawing is one of those things most of us believe we can’t do. Young children make marks instinctively, often long before they can talk, but as they grow up they tend to lose the drawing impulse, disheartened by the perception that others draw better. Drawing is being squeezed out of the curriculum, and the art world’s love affair with computers, video and installation has led to the closure of art school drawing studios.

But there are drawing evangelists out there: notable artists and illustrators, mathematicians, designers and architects who believe the tide must be turned; that to draw is to see more truly and to see is to understand the world around us more deeply. This weekend, children and adults are being invited to take up pencil and paper for The Big Draw at more than 350 venues across the UK. The British, Science, Natural History and Vamp;A museums; the Tate galleries in London, Liverpool and St Ives ; shopping centres; National Trust gardens; railway stations; church halls and provincial museums and galleries - all will be involved, opening up collections and providing materials for people to make their mark.

In Surrey, Kingston University and the nearby Bentalls shopping centre aim to enter the Guinness Book of Records with the world’s longest drawing; the Isle of Skye is staging a Festival of Scribble; and children in the Midlands are helping to design the finale of the Walsall Illuminations with fire drawings. Anyone who has ever wondered what drawing sounds like might find some answers at Kettle’s Yard, Cambridge, where composers Richard Baker and Tansy Davies, with artist Anna Towley, will transform visitors’ “graphic scores” into a performance. At the Ikon Gallery in Birmingham there will be a fax link to the city’s Habitat store. Shoppers will be able to make a drawing and fax it to the Ikon - where visitors will add to the drawing and fax it back. Artists will offer encouragement at both venues. The event will celebrate drawing in all its forms - murals, mosaics, mazes, cartoons, charts, maps, smoke trails and choreographed skateboarders and dancers.

This is the Big Draw’s second year, expanded as part of a three-year initiative by Drawing Power, the Campaign for Drawing, which has struck a chord with the nation since the first Big Draw. Drawing Power was set up to mark the centenary of John Ruskin’s death by the Guild of St George, a tiny charity founded by Ruskin. He drew almost every day of his life to train his eyes, as he put it, to see more clearly. He believed drawing was the foundation of visual thought. The campaign has attracted substantial funding and wide interest.

Artist David Hockney, one of the patrons of the campaign and well known for his photomontages and fax and computer-aided images, has reaffirmed his commitment to drawing and readily echoes Ruskin’s sentiments: “If you look at things with a pencil and paper in your hands you are going to see far more. The world has lost so much with the demise of drawing.”

Other patrons include mathematician Sir Roger Penrose, architect Richard MacCormac and opera singer Robert Tear, who wants to show how drawing furthers understanding and analysis.

Tear, who says he suffers from “drawing incontinence”, grabs time to make “philosophical” cartoon studies “everywhere and anywhere”. He says:

“Mark-making is a way of expressing what’s inside you and can be a great release of tension.”

Illustrator Quentin Blake, the previous Children’s Laureate, is also a patron of Drawing Power. He kicked off a preliminary Big Draw at the British Museum last month, which attracted more than 2,000 people and 50 illustrators and artists. Blake, along with Peter Brookes, Michael Foreman, Gerald Scarfe and Posy Simmonds, created a 30ft Big Draw banner. Posy Simmonds says: “It was an extraordinary scene. I have never seen so many people of different ages drawing together. There were paper and pencil shavings all over the floor. I believe anybody can be taught to draw and through drawing they will better understand what they see.”

Quentin Blake says drawing needs to be rediscovered for enjoyment and for developing the intellect. “I’ve been doing it for 65 years and I like it, and I think the public will like it. When you draw from life, if you go back to that drawing a month later you will find you have drawn something characteristic of a tree or expressive of a person’s face, something you cannot get from a photograph.”

Sue Grayson Ford, who founded London’s Serpentine Gallery and is a campaigner for public engagement with the arts, is directing the Campaign for Drawing, which this year extends its brief beyond The Big Draw thanks to pound;112,000 funding from the National Endowment for Science, Technology and the Arts (Nesta). The campaign’s two-year education programme, Power Drawing, is being launched in 100 trial schools, with others joining shortly to investigate the educational function of drawing across the curriculum.

Eileen Adams, associate professor at Middlesex University and an authority on art, design and environmental education, has written the Power Drawing booklet, with illustrations that will provide teachers with a framework for drawing to develop skills of perception and communication and indicate strategies for manipulating and developing ideas. “We want to look at how drawing can stimulate learning and to produce the necessary evidence. We regard teachers as co-researchers,” she says.

A third element of the Campaign for Drawing is the creation of a Drawing Research Network, which will establish links between researchers on drawing.

Nesta chairman Lord Puttnam says drawing should be promoted as a crucial life skill. “It stimulates problem-solving, discovery and innovation throughout design, technology, the sciences and the arts.”

Details of Big Draw events and the Campaign for Drawing on www.drawingpower.org.ukThe Power Drawing booklet is available free from The Campaign for DrawingPower Drawing, 7 Gentleman’s Row, Enfield. Tel: 020 8351 1719.Details of Power Drawing and the Drawing Research Network from Eileen Adams on edu@drawingpower.org.uk