The Underpainting and The Overpainting
“Indirect Painting” simply refers a painting that is done in multiple layers. The first coat (also known as an ”underpainting”) is laid down, and once that has dried, successive layers (also known as the “overpainting” also “glazes”) are added to give the painting richness, luminosity and depth of color. This method was first perfected through an adaptation of the Egg Tempera painting technique applied by the Flemish painters, and later refined and adapted in Italy by the Venetian artists. Since then, there have been several variations of these methods, but I am only interested in looking at these two methods in this article.
-Aaron Holland
Flemish:
Johannes (Jan) Van Eyck was one of the most famous artists of Northern Europe (Flanders)during the 15th century. Although he is incorrectly thought to have invented oil painting, he is certainly one of the great innovators of that medium. It was more likely that, his remarkable technique, and experimentation with different oils and resins, earned him the lasting title as ‘the father of oil painting’.
His background as a Manuscript Illuminator gave his work a highly-polished attention to detail, which is recognizable even today. His paintings would have been painted in Egg Tempera, the common medium of the day, and that used by Illuminators. This medium is characteristically a dull, flat medium that renders objects in a crisp line and a distinctly two-dimensional form. In the hands of a master like Van Eyck, luminous effects could be achieved, but Egg Tempera, because of its inherent limitations, proves a challenging medium to do this with. He was obviously dissatisfied with it as a medium to represent the natural world, because he experimented heavily with the use of oils as a way to create more realistic effects.
Van Eyck found that by mixing the pigments in oils, and then glazing them transparently over the top of the Egg Tempera, the resulting effect from the oiled surface was a jewel-like brilliance. He could blend more subtly, and create more depth than the tempera by itself would allow. His innovative use of transparent glazes over a monochrome underpainting increased his ability to paint highly realistic scenes; This two-step method was not only sound, it yielded effects that were hithertofore impossible. This technique was especially well-suited for painting objects such as: reflective metals, gemstones, glass, drapery, natural lighting effects, and etc…
To understand Eyck’s technique better, let us look at two distinct and separate parts to each Van Eyck painting:
The Underpainting : Translucent Egg tempera on white panel.
Van Eyck’s Underpaintings were painted, much like other artists of the day were doing, using Tempera on a wood panel that was gessoed white. This was an accepted medium, and the methods and materials would have been commonly understood by artists of that day. To keep it simple, his underpaintings were painted mono-chromatically. (Highly detailed drawings were made into cartoons and then transferred to the panels to work from, prior to painting.) *This is an intentional oversimplification, as this description is intended to state the general working methods, and not be a treatise on methods and materials.
The Overpainting: transparent glazes using a nut oil and resin.
Once the underpainting had dried, it is believed that Van Eyck used a mixture a nut-oil( Like walnut or Flax) and a resin, to create a glazing medium that was both stable and durable: That was his greatest contribution to the art of oil painting. He suspended color in his oil/resin medium. The pigment was thinned so that it was transparent, and thin sheets of color were applied on top of the Underpainting until the desired effect was achieved.
An examination of Van Eyck’s paintings reveals this process quite clearly. In the examples (above) by Van Eyck, you can see how the entire painting was first painted in the monochrome, and then the colored areas were added afterwords in a glazing process; This is now known as an “Indirect Method” of painting.
*It is understood that the Flemish painters kept the darks somewhat transparent throughout the entire painting, by avoided mixing any white into them.
Venetian:
Tiziano Vecellio, better known as Titian, (a pupil of Bellini and Giorgioni) was a leader of the 16th-century Venetian school of the Italian Renaissance. Below is a rare (unfinished) underpainting by Titian, that shows how he worked:
The Underpainting: Opaque, Greyish or Greenish monochrome, painted in oil paint.
In contrast to Van Eyck’s approach, Titian almost always painted his Underpaintings in monochromes that were greyish in color(and/or greenish-greys) as seen in the unfinished painting above, unlike Van Eyck’s brownish underpainting. Another difference is that we know he painted the entire painting opaquely- even in the shadow areas, and probably painted them on a toned ground. Another notable difference is that the entire painting was completed in oil paints, whereas Van Eyck used Tempera for the underpainting. When Titian finished an Underpainting, he would set it against a wall and allow it to dry for about six months before resuming work on it, presumably because the oil paint needed to dry .
To clarify, he painted the underpainting in a opaque greyish monochrome, allowed it to dry, and then glazed transparent color over it until the painting was complete. Although the technique is slightly different than Van Eyck’s , the same two-step mathod is at work here:
The Overpainting: transparent Glazes of color using a nut oil and resin, similar to Van Eyck.
Titian applied many layers of these transparent glazes, so thinly, that it is probably impossible to detect, even with modern means, how many layers he painted. The multitude of layers that Titian painted, would account for the softness of form and delicacy of color that is so characteristic in his work.
Titian’s use of a greyish/greenish underpainting, and warmer glazes overpainting, can be seen in many of his paintings.
The Demonstration:
I have created this painting demonstration using a “two-step process” similar to what was looked at in both Van Eyck’s and Titian’s paintings (though closer to the Venetian approach than the Flemish) to show that this two-step approach can still be used today. My goal was to achieve depth and luminosity through transparent glazes (overpainting), on top of an opaque Underpainting.
The Two Steps are:
1. The Underpainting- opaque monochrome
2. The Overpainting- transparent glazes
I will be using a ‘Greenish Umber+ White’ underpainting sometimes referred to as “Verdaccio”(instead of a Raw Umber + White color like Van Eyke might have used). Theclassic greenish underpainting, when used under flesh, has a natural tendency to neutralize the reds in the over painting, and causes the shadows to loose chroma naturally.
It is crucial that the underpainting is completely dry before any glazes are applied. The use of Egg Tempera for an underpainting was a good choice during Van Eyck’s life, for a number of reasons, among them, a fast drying time, and a stable surface (when painted on a stiff support). I have decided to use Alkyd Oil paints on canvas, in place of Egg Tempera or traditional oil paints, because I prefer working in oils, but still want a fast drying time.
Before Alkyd based oil paints were invented, if the artist wanted to work with oil paints for the underpainting, they would, by necessity, need to wait up to six months before they could add the Overpainting (Glazing). Because of the advancement of Alkyds however, an artist now can use oil paints in the same way that Tempera would have been used for the underpainting. Alkyds cuts the down the waiting time to a practical amount of time, and so have become a viable substitute in place of Egg Tempera for this process.
Step 1: The Underpainting
As you can see the drawing has been previously finished and was transferred to a toned panel or canvas prior to painting.
I applied the paint with china bristle brushes for the first step, and thin the Paint with Mineral Spirits, just enough to make it workable, but otherwise keeping it opaque and near tube-consistency. The Fat-over-lean principle is as work here: by NOT introducing an ‘oily layer’ in the underpainting, I do not have to worry about trapping oil in this layer.
I am using one color, plus white, for the monochrome, in this case, a Greenish-Umber plus Flake (Lead) White.
Cover the canvas, painting directly, wet-into-wet. The Alkyds dry in only a few hours, so it is imperative to work quickly. A second coat can be painted if the first is not quite perfect, so it is not necessary to get it right on the first go.
Minimize brushstrokes as you are painting. The surface needs to be smooth (a glass-like surface is highly desirable for glazing). It should be free from texture as much as possible to ensure a proper surface to glaze over, otherwise the pigments settle into the ridges, creating unwanted and undesirable effects.
The over-all value range of the painting should be kept slightly lighter than the intended values*, as they will be darkened slightly with the addition of glazes.
*Notice that even the darkest darks have a little white in them to lighten the value and create opacity in the paint.
Continue in this manner until the canvas is covered and the painting is complete and fully-rendered.
You goal for the “underpainting” is to have a finished monochrome painting, but without the addition of color yet.
This should resemble a finished painting, as much as possible, before moving to the ‘Glazing of Color’ step. The more complete the painting is at this stage the better it will look as a finished painting.
(In Van Eyck’s case, he took the monochrome painting stage to a photo-realistic level before adding any glazes whatsoever.)
Although minor corrections can be made through the entire painting, it is certainly easier to do them before glazing than after the glazing has been started, and usually yields a better finish.
It is important to allow the underpainting to dry thoroughly before beginning the second step.
The paint should be completely dry before beginning the next step to ensure that you don’t paint over something that is still drying (in other words you want to avoid painting over drying paint as it will still be expanding and contracting). By doing so you risk trapping those areas of drying paint under another layer, and not allowing them to oxidize properly, and thereby risk cracking of subsequent added layers in the future.
Although Alkyds were not the traditional medium used for Venetian Painting methods, the necessity for a completely dry painting makes them essential. If we are approach to this Indirect painting method today, unless we are willing to wait 6 months to a year between the two steps, we need to take advantage of the modern ‘Alkyd Paints’ for our under-layer.
Alkyds dry very quickly. The thickest, most heavily painted areas, will be the determining factor in how long your wait time is, but generally should not be more than a few days, up to a week, and for thinner areas sometimes overnight is enough drying time.
Step 2: Glazing
Once the Underpainting is dry I can begin adding color (I used what is referred to as the Paxton palette for this painting- named after the artist Wm. Paxton).
For the glazing step on this painting an alkyd medium can be used to speed up drying time (such as Liquin or Galkyd- any of the other synthetic oleoresinous mediums on the market can be used with equal success). I also switch to softer, sable brushes for this step.
I started in the background, and “oiled out” an entire area (as much as I felt I could paint in one day). To “oil out” an area, I spread a thin layer of oil (Liquin) evenly over an entire passage. It doesn’t matter where you begin, but try to choose an area that can be started and finished in one day because the oil will dry overnight.
Moving into the face (and other parts of the painting, my process is the same. Oil out an entire area, in this case the face, and start by adding thin ‘veils’ of transparent color to the darkest areas with the sable brush. A new (dry) sable brush can be used to blend the colors to reach desired result.
Because multiple layers can be added- the final effect does not have to be achieved in one go. ’Glazes, thirty to forty’ is an oft quoted statement attributed to Titian, supposedly referring to how many layers of glazes he painted in each picture.
While the oil is still “open, or workable, it is important re-state the light areas by scumbling a white paint directly into the highlights and lighter areas, re-establishing values. When this step is done allow to dry. Liquin and other fast drying mediums will dry over-night and can be painted over as soon as the next day.
Once the oil has been applied to an area, start by glazing in the dark areas to add transparency. In other words, start with the darks first, and mix the color you wish to use on your palette with enough oil to make it transparent. It is very much like painting with watercolor, in that you want to add layers of transparent colors, to gradually achieve a sense of depths and form. Avoid adding any whites or other opaque colors to these dark areas.
While the oiled-out areas are still “wet” (workable) pull out the lights again by painting the light on the form with white.
If you think of the form as dark, halftone and light, it can be approached like this: add transparent darks first, leave the underpainting to show through in the halftones, and add/restate the whites and opaque colors to the highlight areas.
Repeat the process until satisfied: Glaze an entire area, paint in transparent darks, and the restate the opaque lights directly into the wet oil. The whites that you added the day before, can be glazed over the next day with a small amount of color. White is a good base for glazing, and so it may be a good choice to use to restate the highlights and light areas. The color can be added again at any point once the values are adjusted.
*hint- Overlap the oil beyond the edges of the area you are oiling out, to achieve a softer transition, or apply the oil just up to the edges for harder transitions.
This process of oiling-out an area can be repeated as many times as you wish.
Multiple layers will consequently darken an area, so you need to make sure your values from the underpainting are adjusted accordingly, but several layers will also add a depth and luminosity to the colors, especially in flesh tone and in the shadow areas where it is important to have more muted colors and lifelike natural light.
Although a final varnish is recommended, it is arguably not necessary, due to the many thin layers of oil/resins that are already on the surface. Once the painting is finished, allow it to dry for up to six months if you decide to add a final varnish.
Aaron Holland Studied at the Bougie Studio with Peter Bougie and Brian Lewis from 1995-98′.