Quiet and understated, Green Earth isn’t a colour that demands attention. It is easily overwhelmed by other colours and tends to melt away in mixtures. However, what it lacks in colour strength in makes up in permanence. It is one of the most resilient artist pigments available, as its colour is unaffected by light, atmospheric conditions, or chemical solvents. For centuries, its use in European painting was most prevalent in Italy. This article examines the history of the pigment in Italian painting, and looks at how the modern painter can get the most from this subtle colour.
Also known as Terre Verte, Green Earth (pigment index number PG23) is soft and gentle with a low covering power and an extremely low tinting strength. It is derived from clay containing the minerals glauconite and celadonite, and it can range from a blue to an olive-shade of green depending on the concentration of minerals and the presence of other naturally-occurring materials, including manganese, iron, and quartz. The pigment has been used for at least two thousand years, with the first written mention of it being found in an Italian source in the 1st century BCE. Some of the earliest known examples of Green Earth in painting are in the frescos of the preserved Roman city of Pompeii, southern Italy, which date from roughly the same time.
Green Earth continued to be an important pigment in Italian art throughout the Medieval, Proto-Renaissance, and Renaissance periods. While the pigment was used widely across Europe, Asia, and the Americas, the rich regional deposits of Terre Verte in the Italian Peninsula meant that it was readily available to Italian artists, and they found many ways to use this delicate colour to its best effect.
Green Earth in Medieval Figure Painting
One of the main applications of Green Earth in medieval Italian art was as an underpainting colour, a technique known as verdaccio that was inspired by Byzantine artists. It would be used as a cool base-layer to neutralise the warm red and yellow colours that were glazed on top. The technique lends optical realism to the face, and creates more naturalistic skin tones. However, the Red Lake pigments that were glazed on top had extremely poor lightfastness (a fact that medieval artists were well aware of) so over time it has faded, revealing the extremely lightfast Terre Verte underneath. This is why we find that certain faces in medieval painting have a sickly pallor.
In another later example of verdaccio, two figures in the background of one of Michaelangelo’s unfinished paintings have been blocked in with Green Earth. The more developed figures show how it acts as a hidden layer, neutralising pink tones in the skin. Green Earth from Verona, with its distinctly blue undertone, was considered to be the best for this technique.
Green Earth in Landscape Painting
From the 17th century in Europe, the landscape ceased to be only a background for narrative subjects, and became a painterly subject in itself. Terre Verte as an underpainting colour came in useful here too. It was used to block in the composition and tonal values and provide an earthy layer for other pigments to be applied on top. At this time, Green Earth’s use in painting was still concentrated in Italy, but it was also taken up by artists from Northern Europe who studied their craft in Italy. In Jan Willemsz Lapp’s Italianate Landscape with Shepherds, you can see how a Green Earth underpainting plays a harmonising role, tying the landscape together:
It is an approach that artists today can use. Transparent or semi-transparent earth colours, like Raw and Burnt umber, are popular for monochromatic underpainting because they dry quickly and provide a cool (Raw Umber) or warm (Burnt Umber) base to build upon. Unlike the Umbers, Green Earth is a very mid-valued colour so it is difficult to establish extremely dark values with it unless it is applied thickly or built up in layers. Nevertheless, its gentleness can be a strength in this context, as it lets you plot the composition without being too intrusive, while imparting a soft earthiness that will shine through in the finished painting.
Mixing with Green Earth
Green Earth’s incredibly low tinting strength makes it a very selective mixer. Add it to some of the vibrant, punchy synthetic pigments and it will melt away without leaving a trace. Because green is complementary to red, it is often used to bring down the saturation and value of red pigments. In the below swatch, Green Earth has been used to adjust various red pigments. What it doesn’t show is the amount of Green Earth paint that needed to be used to make a different to Cadmium Red and Quinacridone Magenta (first and second rows). A stronger green like Viridian or Phthalo Green would have been more efficient in changing these strong reds. It held up much better With Manganese Violet and Alizarin Crimson, and with them made some interesting greys and browns.
In the below mixing chart you can see how quickly the Green Earth disappears when mixed with Titanium White. It is a rather lovely companion to Raw Sienna, making some olive-greens that would be helpful in a landscape palette. Nickel Titanate Yellow is one of the lowest-tinting yellow pigments available today, so it makes a good match with Green Earth. Finally, with Benzimidazole Orange, an intense modern reddish-orange, it makes a spectrum of browns.
The two above mixing charts differ in one key aspect- in the first Green Earth was added incrementally to the other colour, and in the second it was reversed, and the other colour was added incrementally to Green Earth. While this was not intentionally done, it made all the difference and illustrates an important point about mixing low-tinting pigments with strong-tinting ones- it was far easier to begin with Green Earth (the weaker colour) and slowly add small amounts of a stronger colour. This way you are able to have more control than if you add large amounts of gentle Green Earth to a powerful colour. Perhaps Green Earth is a versatile mixer after all, as long as its incredibly low tinting strength is taken into account.
If you have any favourite mixtures with Green Earth, let us know by leaving a comment below.
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