The advanced watercolor painting technique, called gouache, first emerged some time in the 16th century, presumably in France. 'Gouache' comes from the Italian word for 'splash.' This method of watercolor painting results in a slicker, shinier final product. Its flexibility as a method has made it popular with neophyte artists. Gouache is comprised of a watercolor admixture thickened by the addition of gum arabic and chalk.

When a gouache painting dries, it may appear slightly darker than expected. Thus, it takes practice to match gouache color palettes. If you apply too many layers of gouache, you can get cracking and flaking. Certain gouache painters add another element, called aquapasto, to the admixture to give the watercolor additional strength and fitness.

Producers of 'decalcomanias' almost exclusively employ gouache in their works. One of the most famous gouache advocates was a man by the name of J. M. W. Turner, who liked to apply gouache to colored paper and canvases. Gouache artists like to explore different thicknesses of their base paints. However, unless you've written down a precise 'mixing formula,' plan on completing your work or series of paintings with one mixture.

Since gouache based liquid can evaporate over the course of a painting session, unevenness may occur. You may want to mix multiple dishes of gouache just in case. Certain color pigments may create odd thicknesses, so stir any irregularities out of the gouache before applying brush to canvas, and never add chalk or thickener in the middle of a painting session.