Watercolour is a painting method where pigments are suspended in a water-soluble vehicle. The term refers to both the medium and the artwork. The most common support for watercolour paintings is paper. Other materials include bark papers, canvas, fabric, plastics, vellum or leather and wood. Watercolours are usually transparent, appear luminous because the pigments are laid down in a relatively pure form with few fillers obscuring the colours. Watercolour can also be made opaque by adding Chinese white. Source: wikipedia (edited).
Artwork needn't be expensive, this colourful works by Derek Smith, a mature self-taught artist from Suffolk who has only been painting a few years. This watercolour simply entitled 'Beach huts a boat and seagull', on paper, 19 x 17cm, selling for only a few pounds, nicely framed would look good on any wall.