Ooly's Rainbow Sparkle watercolour gel crayons make bold strokes of colour, which magically change when you add water. They're made with a solidified gel for bolder and smoother strokes than normal crayons. Then use a wet paintbrush for super watercolour effects. The crayons work brilliantly on black paper too! This set of 12 crayons has a thick, contoured grip that makes them easy and comfortable to use.