Bigger Trees Near Warter (2007)is David Hockney’s biggest work to date. It portrays a typically grey day in East Yorkshire. ‘Bigger Trees Near Warter’ – David Hockney

The painting was given to the Tate by the artist two years ago and is currently in the Royal Academy Hockney exhibition. The oil painting, valued by the Tate at £10m, is undeniably huge, made up of 50 canvases and measures in total 15ft by 40ft (4.6m by 12.2m). "I think it looks very good. It's quite an effect, isn't it?" said Hockney. "Funny to think it was painted in a small room in Bridlington’’

The original place that inspired the painting.

Hockney is a vocal advocate of new technology but he also believes that the craft of painting is alive and well. “Technology allows us to do all kinds of things today, but I don’t think anybody previously has thought that it could help painting. A great big landscape, on a big wall – that’s what the Royal Academy should be encouraging,’’ Hockney

Hockney paints directly from experience, setting up large canvases in the countryside of East Yorkshire. "Once you live in a place like California, well, you need the rain. I used to think there were dull days and now I think it's only you … dull people."

How did he begin this painting? Hockney first spent time just looking at the subject he was going to paint. ‘I would go and sit there for three hours at a time, just looking, lying down practically so I looked up.’ The subject of the painting is one of several spots in the landscape west of Bridlington where he has been working. It consists principally of an immense net of interconnecting twigs and branches. He says that it is only by looking very long and hard that you begin to understand what you are seeing. “A picture this size just has to be of certain kinds of subject. Nature is one, because there is an infinity there that we all feel.’’

Next, he began to make drawings, which weren’t detailed, because he didn’t want to make a painting that was simply a blown-up drawing. He used the drawings to locate where each canvas would go in the composition. The painting itself was essentially done in one three-week sprint. “The painting had to be done in one go. Once I had started, I had to carry on until it was finished. The deadline wasn’t the Royal Academy. The deadline was the arrival of spring, which changes things. The motif is one thing in winter, but in summer it’s one solid mass of foliage – so you can’t see inside and it’s not as interesting to me.’’ Hockney

For Hockney, as for Monet, the most crucial difficulty of painting a huge picture outside was the problem of stepping back, in order to relate each part of the work to the rest of the image. However, that was soon solved by digital photography, in conjunction with computer technology. As Hockney worked, his assistant constantly photographed what he was doing and then fitted the images into a computer-mosaic of the whole picture. This enabled Hockney to step back, albeit in virtual space, so that he could see what he was doing. However, the artist certainly didn’t want to create a photographic look in the final work. Executing a big painting outdoors was a project that gripped several nineteenth- century artists including Constable and Monet (who had a trench dug, into which his Le Déjeuner sur l’Herbe was raised and lowered, so that he could work on different parts of the surface).

Close up to the surface, the painting consists of quick, free, calligraphic brushstrokes. Hockney has been painting ever more rapidly in recent years but never with such verve as he does here. He combines the virtues of the on-the-spot study, its speed and immediacy, with the carefully considered monumentality of the studio picture.

Inspiring your students… Get them outside! Record landscape digitally, to use in the classroom Rescale and experiment with overlapping sections Quick studies of trees, roots, branches Seasonal changes studied through photography Experiment with paint – tactile, loose, expressive, inventive Bring greenery into the classroom Create a nature reserve Use collage, fabric, print, recycled materials to recreate sections of a landscape/wood..