The least well-known of Warhol’s works are his Camouflage, Oxidation, Rorschach and Shadows paintings. With their lack of an obvious representational subject they are at odds with commonly held notions of the artist’s work. In his early Pop days, Warhol had made images of Coke bottles, celebrities and soup cans appear abstract by repeating and enlarging them, or transforming them with colour. These later works pushed this tendency even further.

The Shadows paintings were based upon a photograph of the shadow cast by an object in Warhol’s studio. The original series was conceived as one painting in 83 parts and when first shown, the sections were hung edge to edge along three sides of a large gallery, so that the viewer was enveloped by their rhythmically repeating forms. Warhol called them ‘disco décor’, and sprinkled other versions of the paintings with diamond dust, creating shimmering surfaces as elusive as the shadows themselves.

The Camouflage paintings create a similar all-encompassing environment. Based on a piece of material from a US army surplus store, they are simulations of nature, suggesting panoramic landscape paintings such as Monet’s Water-lilies. The subtle atmospheric effects of the Oxidation series were created by unorthodox means. Each canvas would be laid onto the floor and coated with copper paint. Warhol, or one of his assistants, would then urinate on them, causing a reaction with the paint.

A side of Warhol’s character he kept hidden from all but his closest friends was his religious faith. Brought up in a fervently Catholic family, he attended Mass throughout his life. The Last Supper is based on Leonardo da Vinci’s masterpiece. By dividing the image into repeated sections, and inverting some of them, Warhol creates an abstract composition in which gestures and postures form a wave-like rhythm across the canvas.