Thomas Girtin was an English watercolourist and etcher. A friend and rival of J. M. W. Turner, Girtin played a key role in establishing watercolour as a reputable art form.

Watercolor or watercolour, also aquarelle, is a painting method in which the paints are made of pigments suspended in a water-based solution. Watercolor refers to both the medium and the resulting artwork. Aquarelles painted with water-soluble colored ink instead of modern water colors are called aquarellum atramento by experts. However, this term has now tended to pass out of use.