British artist Barbara Nicholls’ (born 1963) watercolours emerge by manipulating the behaviour of pigment in ever-increasing quantities of water that result in an immense richness of nuanced and vibrant colours. Reminiscent of gemstones or excerpts from nature in a wider sense, Nicholls researches and experiments like a scientist or alchemist to reveal the microcosms of our planet. Painted on a sheet of thick watercolour paper Over Under bears traces of water and pigment echoing sediment flowing through a riverbed, patterned rocks or sands are laid bare by the warmth and illumination of sun and wind. Organic patterns and shapes reflect...