Q. I’d like to begin painting in egg tempera, but I’ve heard that traditional acrylic gesso won’t make a good ground. Is there a safe, pre-mixed alternative?
Oak Hill, WV
A. Traditionally made from egg yolks and ground pigments, egg tempera has been used for centuries. Over time, oils and acrylics have become more popular because of their greater ease in manipulation. Many artists still cherish egg tempera, however, for its clarity of color, its crisp lines, its velvety appearance with just a hint of sheen, and even for the demands of applying such a precise medium well.
It does have limitations regarding grounds, however. Egg tempera is generally used on gesso grounds of hide glue and chalk over solid supports such as wood panels. You should easily be able to find mixes of dry glue and chalk, to which you can add water to mix your gesso, but you can’t purchase it in the liquid form. Glue grounds are easily worked into a smooth surface, they’re very absorbent, and their whiteness doesn’t discolor with age. But the drawback is that hide glue has a limited shelf life once it’s mixed, so you’ll have to mix it up fresh when you’re ready to use it.
I’m unaware of any long-term studies that examine the aging of egg tempera paint layers over acrylic grounds, but I can think of some concerns that you should be aware of. The flexibility of an acrylic ground, which is considered one of its greatest advantages, is a potential disadvantage in this case. Egg tempera is relatively brittle (the reason it’s usually applied to a solid suport), thus the flexible ground may make your paint layers more likely to crack.
Egg tempera can also crack and flake off if applied too thickly, so most technical manuals advise applying it in thin washes mixed with water. It’s for this reason that the absorbency of the ground is important, and acrylic grounds are known to be less absorbent than glue grounds. An acrylic ground used with egg tempera, therefore, runs the significant risk of adhesion problems between the ground and the paint.
If you don’t want to mix your own ground layer, you could consider applying your egg tempera on paper supports. Paper doesn’t require a ground layer when using tempera paint, but its flexibility may become a problem (as with fabric supports) so you may want to use a paper board or some other auxiliary support to provide rigidity.
Catherine Anderson is a Signature Member of the American Watercolor Society and the author of Basic Watercolor Answer Book. Her DVD, Creating Multiple Glazes in Your Watercolors, is available now on her web site www.catherineanderson.net.