Victoria Finlay writes about verdigris in her beautiful book Color (or Colour if your in Europe):
Verdigris is often described as coming from somewhere else. So ‘verdigris’ means ‘Greek Green’ in English, while the Germans call it Spanish Green, ‘Gruenspan,’ although it probably arrived in both places via the Arabs. The Greeks themselves describe it as ‘copper flowers,’ or more vividly ‘fur tongue,’ perhaps because of how the verdigris deposit on the copper plate looks like how one’s mouth feels after a heavy ouzo session. In France this paint was usually produced by the vineyards; in England it was often made with apple cider vinegar.
In The Craftsman’s Book (Il libro dell'arte from late 1300’s) Cennino Cennini wrote that verdigris is a beautiful green that is “manufactured by alchemy, from copper and vinegar.” He continues: “[…] if you want to make the most perfect grass color imaginable, take a little verdigris and some saffron.” Beautiful as it may be, Cennini alerts us that “it does not last.”
Leonardo Da Vinci, also, was vary of employing verdigris, and warned that if it isn’t varnished quickly, it’ll vanish into thin air.
Still, some artists used it with success, in the sense that the color isn’t ruined even centuries later. The Dutch master Jan van Eyck, for instance used it so much and with such eloquence, that verdigris sometimes is called van Eyck Green.
If it is mixed into oil to make oil paint, verdigris changes (over a period of a few months) from the pigment’s original blue-green into a deeper leaf green.
Modern tests and science literature — for instance Hermann Kühn in Artists’ Pigments: A Handbook of Their History and Characteristics — suggests that verdigris is not as harmful as some of our earlier sources has claimed. However, Kühn warns against using it on paper, because “verdigris, in common with other copper pigments, will degrade cellulosic materials.”
I have no personal experience as to whether it’s good or bad as a paint pigment, but I do know that it’s fascinating to make:
I poured a little bit of vinegar at the bottom of a glass jar. I then put a piece of copper pipe in the jar, but laid it on top of some plastic scrap, thus securing that the copper didn’t directly touch the vinegar. The intent is to only have vinegar vapor (and not the fluid) touch the copper. And then I sealed the jar and left it on a shelf in the shed for a long time (days? months? years?). And then, just as I thought I had forgotten about it I realized that I hadn’t forgotten about it and I took it out and it looked like the photo above.
As Katy Kelleher once wrote in The Paris Review, verdigris is “a color made from change.”
The natural world is mysterious and beautiful.
Bibliography
- Cennini, Cennino, and Daniel V. Thompson. The Craftsman’s handbook. New York: Dover, 1933.
- Finlay, Victoria. Color: A Natural History of the Palette. New York: Random House, 2004.
- Kelleher, Katy. “Verdigris: The Color of Oxidation, Statues, and Impermanence.” The Paris Review. November 24, 2020
- Kühn, Hermann. “Verdigris and Copper Resinate.” In Ashok Roy (ed.) Artists’ Pigments: A Handbook of Their History and Characteristics. Washington: National Gallery of Art, 1993.