Ten children are working hard, hooked on the joy of playing with paint and seeing a finished piece emerge. They have only 45 minutes to create a vibrant, imaginative flag to be used at Notting Hill carnival in August, and we need to finish 200 flags in just three days.

The children can choose any colour for the background, and they have endless supplies of tools and brushes, crayons, thick oil paint, watercolour, ink, bleach, marker pens, scrapers, palette knives, airbrushes, luminous pens and charcoal. Is this really a state primary school?

Children add sparkles, flowers and spirals to their flags. There is delight in the rainbow light bush, the neon pen and the madras brush, which fills the page with divine squares of transparent colour. I have to prise the children away when the session ends, which I can do at the very last minute as there is no need to wait for the paint to dry and no set-up time required before the next group come in.

The reason is that our art room is actually the school's ICT suite, and the children are painting on computer. The paint dries instantly.

I am a professional artist and began with canvas and paper but later went digital with the arrival of my first baby, Sasha, in 1990, and my first computer soon after that. How would I manage to keep going with baby things taking over the studio? I later learned it was almost the same dilemma as fitting expressive art sessions into the national curriculum.

But after seeing a piece of software called Painter demonstrated at a computer show I saw a way forward - a computer desk in the corner of the room was all I'd need.

I now paint almost exclusively on computer, but my work process is still fast and messy. I specialise in working live and am commissioned to paint at events from international conferences to film shoots.

My last 'real-paint' paintings were for an exhibition at the Royal Festival Hall while commissioned as artist to the Royal Philharmonic Orchestra - a dream job and a year of carrying reams of paper and paints between my studio and rehearsals, concert halls and tours abroad. I breathe a sign of relief that my kit is now more portable with sketchbook and entire studio being a Powerbook laptop.

When Sasha, by now aged five, started bringing computer art home from school, it seemed much less sophisticated than what she did at home, so I ventured into her state school - Fox at Notting Hill Gate - to see if I could help.

As in many schools then, the equipment on offer was stand-alone RM computers and very basic, mouse-based drawing software. So I begged the loan of six Apple Macs for two weeks - in those days Painter worked best on a Mac - and designed a project for 250 children.

They took to the pressure-sensitive pen and drawing tablet immediately. "It's just like a splodgy paintbrush, but you don't have to keep dipping it in the paint, and your picture doesn't end up all greyish - it's like magic!" said one young enthusisiast.

It took the full two weeks to get through all 250 children. We covered the school hall with brightly coloured A4 printouts and, after a long session uploading, won first prize out of every school in Britain for having the most work on the Tesco SchoolNet 2000 website.

My own professional jobs are printed directly from disk on to large canvas, fabric or Perspex for hanging in corporate interiors. My computer equipment has grown with the powerful sophistication of the software. From huge digital murals for Hong Kong Telecom to drawing live on an Apple G4 Powerbook with a projection screen at society weddings, my faithful tools have been a computer, a Wacom digital drawing tablet and Painter software.

That might sound like a different world from the average school's ICT suite, but the exciting thing is that the software and digital tablets are now refined enough - and inexpensive enough - to run on any school computer, Mac or PC. An ICT suite that doubles as an art room is now very possible, and the latest Wacom Volito drawing tablet comes with Painter software free in the box... an art room for just £40 a computer.

Indeed, professionally printing children's artwork on fabric for Notting Hill carnival, which is how the flags will end up, is only possible with sponsorship. The Arts Council funds my work with Fox's carnival float - but school projects without funding, which I squeeze in between professional jobs, have been equally successful and rewarding.

Just seeing full-colour inkjet prints of children's work collaged together on a wall gives endless possibilities for further ideas - we've had Egyptian scenes, jungle habitats and digital cityscapes to line our corridors. Painting with bright watercolours on a black background - something you can't do with real-life paint - has produced some fantastic night scenes. As as long as there's money for ink cartridges, a project can succeed.

The Digital Cityscape, Fox children's paintings of buildings, won a Clore Duffield national artworks award, but one of the best moments was working with a very introverted year 4 child from a north Kensington school, and seeing him just grin with delight as he finished painting the face. His teacher, with tears in her eyes, had not known that he liked to paint.

Working with children's raw creative energy and uninhibited expression always leaves me awestruck and exhilarated, and it keeps my own work fresh. Playing with paint and colour is expressing yourself and should be a fundamental part of every child's education.

This was something that hit home recently during a session I ran for teachers when they were thrilled to discover and play with two Painter brushes called Big Wet Luscious and Flemish Rub. But what really fuelled the giggling was the simple joy of painting, something everyone needs to do now and again.