By making use of Penny Soto's detailed knowledge of watercolour pigments and how they work together, readers are able to learn how to combine and juxtapose colours in a way that will make watercolours seem to glow from within. She uses step-by-step photographs to teach readers how to choose a carefully chosen underpainting. This is one of the techniques that makes colours glow, and readers will practise this with mini-demonstrations and illustrative instructive art. She also guides readers on light, backgrounds and shadows, with a special chapter on using underpainting to paint reflections in water.