Several people have come to my website over the years as a result of conducting web searches for gouache painting (pronounced “gwosh” or “goo-wash”), likely led there by the numerous gouache paintings listed on the place. There is some conflicting information published on this topic. Accordingly, this article is to help you better understand this opaque watercolor medium based on over thirty-five years of experience in its use and as a professional art educator.

Supposedly, the ancient Egyptians first employed this paint and its use was later refined by the Italians, whence we get the word that originates as aguazzo or guazzo. This is said to refer to “mud” or “watercolor paint, splatter”. It is sometimes used interchangeably as body color and designer colors. Supposedly, guazzo was also an idiom to describe the 16th-century technique of applying oils over tempera paint. However, gouache paintings were exploited by illuminated manuscript artists and were later popular with some European decorative artists as well as landscape and nature artists such as Albrecht Durer. Because opaque paints dry quickly and can be applied with a flat, even tone, during the 19th century gouache was often the favorite of architectural and advertising illustrators; thus, the paint earned its nickname “designer colors”.

A body of gouache paint is made up of several elements, including pigment and an opacity agent. These density additives differ by manufacturer. Some contain blanc fixe (French for permanent white); in this case its barium sulfate (also used as a filler in papers). Other manufacturers incorporate calcium carbonate, better known as chalk, or “precipitated” chalk (technique for synthetic). When the water container is emptied to rinse the brushes during this painting process, the thickening material can be seen as sludge at the bottom of the container. Gum arabic is the binding agent that all gouache paint manufacturers adopt to bind the ingredients together. In some cases, glycerin and preservatives are also mixed. The main differences between transparent and opaque watercolors is the addition of a calcareous substance and the amount of gum arabic; gouache contains a higher concentration of the latter. When gouache is applied as an impasto, it is gum arabic that can give dried paint a pearly patina. If used too thick, such as with tempera, the paint will crack. Typically, a gouache painting will have a dull surface appearance. This makes it ideal for photographic reproduction purposes and is another reason why it has been popular with illustrators.

Some sources I’ve read say that gouache comes only in tubes. That is not like that. I have a set of Pelikan pans that I bought in my teens when I started using this type of paint in the mid-1970s. These pans, called “cake” shapes, have the advantage of being able to purchase replaceable colored cakes. and an integrated palette. Because gouache paints can be re-wetted and reworked when dry, as the pastels empty you can squeeze the tubes of paint into the receptacles on the pastels. Gouache tubes are said to have a shelf life of 3-5 years, which is when the tubes solidify. When this occurs, I open the tubes and use the dry form just as I do with the cake variety. I sometimes use a single edge razor blade to shave the necessary amounts onto a palette. Apparently, gouache can also be bought in liquid form, but only in small black or white jars. These are probably the only two available because they are the two colors that are used the most and the high opacity content causes them to sit in jars.

Some benefits and uses of gouache have already been covered, but there is more. Because gouache painting materials are easily portable and dry quickly, like transparent colors, they are ideal for outdoor pieces (painting en plein air), and some artists have used gouache as preliminary sketches for larger oil paintings. . As stated above, gouache can be re-wetted after it dries, so plein-air paintings can be reworked in the studio. This quality also allows the colors to blend and blend gradually into the paint surface. Also, gouache works well on tinted papers and can also serve as a base for pastels.

Wet-on-wet, drybrush, and splash transparent watercolor techniques can also be achieved with gouache. However, due to the opacity of the material, the paints do not bleed or bloom in both wet-on-wet and transparent colors. Liquid masking agents can also be used to block out areas and leave them white, although most gouache artists only take advantage of white paint. As you may know, “frosting” in painting is the process of painting one thin, diluted layer of color over another. Again, due to gouache’s chalky substance, many believe that gouache cannot be glazed. However, to solve the problem of the base paint mixing with the diluted paint as the glaze is applied. I spray a single coat of fixative (the same thing used on pencils, chalks, and pastels to prevent smudging) over the work and let it dry. Then I glaze over an area, particularly for the shadows. There are two concerns in doing this. First of all, the fixer can’t be too thick or else the paint you put on top will pool and not cover. The second must also be taken into account and planned. You can change the color, especially by washing thin layers of white areas. I will refer to this again when I talk about finishing paints. In addition, I have also successfully used gouache for airbrush painting, such as in “Family Outing” and “Morning Stretch” paints.

The ability to mix with other water-based paints is another admirable feature of gouache, especially with transparent watercolors. It’s been said that gouache doesn’t mix well with acrylics because the paint sticks, thinks it curdles, like cottage cheese. I’ve never had this problem, but then I don’t use much gouache from tubes added directly with acrylic paint, just small amounts. The way I mix them works pretty well. However, since acrylic dries like plastic with a slippery surface, to paint gouache over acrylics, a thin layer of fixative must be applied to allow the gouache to adhere.

Any watercolor paper used for transparent watercolor painting can be used with gouache. Smooth or hot-pressed corrugated papers 140lb or thicker work well. I prefer to use mounted rag paper called watercolor board made by Crescent. Another paper I’ve had success with is a four-ply rag paper used in museum setups. I moisten this paper and then stretch it on a wooden frame made one by two. Softened cotton paper is stretched and stapled like a canvas.

When it comes to finishing and displaying gouache paintings, there are numerous issues to consider. The most common way to approach gouache for framing is to handle it the same way you do with transparent, matte, and framed watercolors under glass. In the mid-1980s I stopped using this method for three reasons. A gouache painting, “Warm and Foggy December,” that I entered into an exhibit at the National Society of Wildlife Art Collectors in Minneapolis, Minnesota, was disqualified from the competition by the judges because they thought the original was a print, no brush strokes were visible on the surface of the paper, it had a smooth, flat surface appearance and was under a white mat.

The second reason has two inherent problems that arise with shipping paintings under glass. One is the increased transportation costs due to weight compared to paintings that are not under glass and the other is breakage. To address these issues, I took a look at how acrylics were handled. Gouache paintings can be finished with any acrylic varnish medium; however, a few coats of fixative should be sprayed so that the paint does not run with the acrylic varnish. This will remove the dull, chalky appearance of gouache and the pieces will look like oil paintings. These photos I put directly in frames without glass. For some reason, I’ve noticed that high-gloss varnish images tend to sell faster than others.

The third reason I prefer acrylic varnish to gouache is the richness and depth it adds to the color qualities of the finished product. Obviously, this means that the colors will change a bit. Consequently, you should practice with this technique several times to become familiar with how it affects paints. When it comes to creating the illusion of water and making it feel really wet, there is no other type of paint I have worked with that does the same job. Since whites tend to wash out, to get strong whites and other bright colors I mix acrylics.

As with any watercolor, transparent or opaque, no matter how the work is framed when it comes to displaying them, make sure they are out of direct sunlight and not exposed to long-term fluorescent lights as they emit a low UV level. radiation that will eventually fade colors, unless under UV protective glass.

Hopefully, you’ve gotten a feel for this versatile gouache medium and aren’t afraid to try it out for yourself. If you have any questions, feel free to contact me.