Gouache (goo-ah-sh or gwaush) is a lesser known painting medium, but has been in use since the 1300s in Europe. Gouache is similar to watercolors in that it consists of pigment and binding agent (usually gum arabic) suspended in water. However, gouache is opaque, with larger pigment particles than traditional watercolors, a higher pigment to water ratio, and added inert materials such as chalk. The larger particles and higher pigment content gives gouache a smooth, velvety look with higher light reflective qualities than watercolors. It is also known as opaque watercolor or bodycolor and is commonly used alongside watercolors to highlight certain parts of the painting.
Gouache as we know it was used as early as the 14th Century in Europe, but is more commonly seen from the 1500s and later. We have historical examples of botanical illustrations from Europe, as well as illuminations from Indian manuscripts and paintings on cotton fabric from what is now Afghanistan. In the 1800s Frederic Remington used gouache to create illustrations which were then sent to lithographers to copy the work for mass book printing.
Claude Monet used pencil, watercolors, and gouache to create humorous drawings and caricatures. Gouache is still prized by illustrators like Alex Ross and Syd Mead today for its smooth and rich qualities.