Watch | Artist who paints only cows

British painter John Marshall has spent the last decade deliberately restricting himself to just one subject: the humble cow. The paintings are big, around 2 metres and, Marshall claims, each bovine has its unique characteristics. The 58-year-old's East Sussex studio, which is ironically a former cows milking parlour, is where Marshall works on his paintings. Photographs are the first stage of the process where he looks to find a cow which engages with him in some way, so when he paints he can tease out and exaggerate the character and nature of his subject. Using a two-foot long brush, he marks out on the canvas where the light should be with black oil paint and turpentine. The painting then evolves to its conclusion and Marshall says it is often the eyes and nose which are critical to ensure a connection with the audience. In the past 12 months he has sold over 40 canvases, which go on sale for up to £6,000 (8,500 US dollars) each. Few find their way into rural homes, as most of the buyers are urban dwellers which seek the surprise of the image rather than any rural connotations. Despite his success as an artist, Marshall's background is not in the fine arts.He started out working at a drawing restoration firm and as a croupier at a Brighton casino. He also served eight years as a civil servant. Marshall started his painting with nudes but on a whim decided to dedicate his talents to just one subject, cows.