Gouache is opaque watercolor. Though it is gaining in popularity, gouache still isn’t as widely recognized as a medium for plein air painting as it should be.
Like transparent watercolor, gouache has the advantages of thinning and cleaning up with water, but, like oil or acrylic, allows for painting from dark to light and working back and forth into areas of change. I think it is a terrific medium for painting on location.
Resources for gouache information are still a bit thin compared to other painting mediums, here are a few sources:
Wikipedia, general article on gouache
Gurney Journey, James Gurney’s blog (link includes a search for “gouache”), with lots of gouache resources and Info
Gouache in the Wild, Gurney’s excellent video on painting outdoors in gouache. (Here is my Lines and Colors review.)
Lines and Colors, this is my general interest arts blog, with a search for “gouache” in the link.
Handprint, this is an excellent source of information on watercolor and, to a lesser extent, gouache.
Some Gouache Artists — Historic
Luigi Loir (Lines and Colors article)
Eugene Galien Laloue (Lines and Colors article)
Stepan Kolesnikoff (Lines and Colors article)
Adolph von Menzel (Wikimedia Commons), also: The Athenaeum, Gurney Journey
James Jacques Joseph Tissot, link is to Wikimedia Commons. Though he painted his society paintings in oil, Tissot did an extensive series of Biblical paintings in gouache. Many are in the collection of the Jewish Museum.
Some Gouache Artists — Contemporary
As I mentioned in the resources section above, James Gurney’s blog contains a lot of information about gouache, as well as examples of his own paintings. You can also find his short videos on YouTube.
Paquette works in oil and gouache (link is to his gouache paintings). His gouache paintings are small in scale and simply beautiful. You can still get copies of his wonderful little book of Gouaches. Here is my Lines and Colors article from 2008 on Thomas Paquette.
Larry Francis is a Philadelphia artist who works in both oil and gouache. As far as I know, he doesn’t have a dedicated website; you can find some of his gouache paintings on the site of the Gross McCleaf gallery. Here is my Lines and Colors article on Larry Francis.
Tiemens is another film industry visual development artist, working for Industrial Light and Magic. He paints wonderful gouache paintings, often in the tradition of 17th century Dutch “Golden Age” landscapes. He has a few videos on Vimeo.
Hernendez is a Production Designer at Dreamworks Animation, and paints wonderfully immediate plein air gouache paintings.
Fowkes is another film industry concept artist who paints plein air in watercolor and Gouache, the “Landscape Sketchbook” part of this gallery page is mostly gouache. You can find more on his blog.
Lena Rivo is a Crimean artist living and working in Portugal. She paints bright, colorful landscapes, particular of beaches, as well as still life and figurative work. She also works in oil, but the link above is to the gouache page on her website. See also: her blog and videos on YouTube and Vimeo
Bradish ia a painter who uses gouache in bold and inventive ways, with strong contrasts, textural brush work and lots of spatter. Link is to his primary website; see also his Behance portfolio and Vimeo videos.