Water colours are a transparent paint based on Gum arabic. Painting in water colour is a technique whereby the paint, thinned with water or as it is, is applied on special water colour paper. The paint has various constituents including pure pigments and Gum arabic, which ensures the pigments adhere to the paper. In contrast to gouache, water colours are always transparent.
Van Gogh Watercolors are:
* Strong colours with the highest possible degree of lightfastness
* Retains colour integrity for a long time, even when thinned a great deal