---

“Gouache isn’t period.” It’s a statement that was often said to me as I started painting scrolls in the SCA and I hear it continue to be repeated to this day. Certainly, the word ‘gouache’ is a more modern invention – the term being applied to opaque watermedia for the first time in 18th CE France; however, the paint itself has been in use for centuries beforehand, just referred to under different terms. But let’s start from the beginning, what exactly is gouache?

Gouache, also known as body color or opaque watercolor, is a water-medium paint consisting of pigment, water, a water-soluble binding agent, and sometimes additional materials. Using a water-soluble binder means gouache dries through evaporation and requires water to be properly mixed (as compared to paints using oils as a binder which dries through oxidation). You may have noticed that watercolors also consist of these very same materials. So what is the difference? It comes down to the ratio of pigment and binder. Watercolors have either equal amounts of pigment and binder or more binder than pigment, resulting in a more transparent paint. Gouache, however, has more pigment than binder – usually at least 2 parts pigment to 1 part binder, resulting in a more opaque paint. To increase opacity, one may also add an opacifying agent (such as whiting chalk or some other form of calcium carbonate) and/or use thicker particles of pigment (think how azurite tends to get paler the more you grind it).

So you may be asking – isn’t this really the same thing? It’s just a different recipe really? Well. No. Modernly, we classify these as different unique paints because painting with watercolor and painting with gouache is essentially different. First, watercolor provides a translucent, lighter finish; while, gouache provides a flat, matte finish even if you were to water down gouache to make it more transparent. In watercolor paints, it is common to achieve a lighter color by adding more water (ex. adding more water to red to create a more pink color). To create a lighter color with gouache, however, you add white paint or pigment instead. 

Additionally, watercolors have a specific way you must layer your colors – from lightest colors to darker colors. If you were to add a lighter color on top of a darker color, it will not show up well. Some artists take advantage of this by using a dark ink drawing first and painting with watercolor on top. The dark ink drawing remains unchanged while the watercolor adds dimension to the piece. If you were to do this with gouache, the lighter color would cover up the dark ink drawing, making it hard to discern. This is because, with gouache, you can layer lighter colors on top of darker colors.

But what about in period? Turns out, we do have evidence that painters also saw a distinction between watercolors and gouache (or body colors or “thick” colors as they were referred to in period documents).  In 1520, the painter’s guild in Bruges, Flanders argued, albeit unsuccessfully, that print colorers, who used “thin” colors, could not claim exemption from the guild as illuminators, since illuminators used exclusively “thick” colors (Illuminating the Renaissance by Thomas Kren and Scot McKendrick, Page 30). Interestingly enough, we see in period examples of a dark ink being used first to draw a scene and then the scene was colored in with watercolor, allowing the drawing to remain clear. A great example of this technique in period can be seen below. In this case, a printing press was used to draw the scene in and then watercolor was used to color the scene. If gouache had been used for this instead of watercolor, we would not be able to see the lines from the print nor would we see the awkward layering of green paint accidentally overlapping the yellow paint as seen on the shoes of the man on the left. The gouache would have covered the lines and the green gouache would have more thoroughly covered the yellow gouache underneath it.

 Cutting from “Heiligen Leben (Legenda Aurea)”, printed by Johann Schönsperger, Augsburg

In contrast, we see examples of a thicker paint in the below examples. The first example, a miniature from the Reed Poissy Processional, clearly shows ruling lines when viewed from the backside of the page; however, from the front, these ruling lines are not visible and are completely covered by the paint.

A great example of lighter colors being applied over darker colors is the below example. This is from a Dutch manuscript of the City of Ladies (~1475). Both pages show a similar scene except the left page is unfinished at the color-blocking stage of painting. This unfinished page has been largely color-blocked in dark gray; while, the finished page has light colored details on the dark gray. If this had been accomplished with watercolors, the artist would have colored in the lighter colors first and slowly shaded using layers of darker colors instead of color-blocking in a dark gray first.

But could this have been accomplished with egg tempera? Yes, actually. Like the term gouache, egg tempera is also a relatively new term, first appearing in the mid-19th century, derived from the Italian dipingere a tempera (“paint in distemper”). In documented recipes, pigments are often “tempered” with a variety of water-based binders such as gum arabic, animal glue, egg yolk, or casein. Museums and conservators refer to these paints generically as “temperas”, which makes it difficult to know what binder was actually used. More research is needed, but this suggests that unlike modernly where we distinguish gouache from egg tempera, there may have not been such a distinction historically.
In conclusion, we see evidence that artists treated and saw a distinction between a thicker paint using a water-soluble binder (what we now label as gouache or egg tempera) and a thinner paint using a water-soluble binder (referred then and now as watercolors). There is also some evidence that historically they did not see a distinction between what we now call egg tempera and gouache, but more research needs to be done on this possibility.