Paint it green

In the process of researching or conserving old pinned insects, it’s common to find a green deposit clustered around the pin. This is known as verdigris and is a natural patina created when the metal oxidizes over time. Katherine Child is Image Technician in the Museum’s Life collections and takes photos of insects for researchers, students, artists and publications. She is also an artist in her own right, so when she witnessed verdigris being removed during a conservation project, she came up with an inspired idea.

A clearwing moth before conservation, showing verdigris spreading where the metal and the insect fats, or lipids, react.

A few years ago I read a book called Colour: Travels Through the Paintbox, by Victoria Finlay, and was interested to learn that verdigris was once used as a pigment. Verdigris, which I now know translates from French as ‘Green of Greece’, is a word that’s been in my vocabulary since I was small.  I loved its rich bright blue-green colour, which is often seen on old copper piping or copper statues.

Verdigris forms when copper or a copper alloy reacts with water, oxygen, carbon dioxide or sulphur.

L: Three years’ worth of verdigris, ground and ready to make into paint.
R: A second attempt at mixing the paint, this time using linseed oil.

As early as 5thcentury AD, it was used in paint-making, and until the late 19th century it was the most vibrant green pigment available. But it was unstable – Leonardo da Vinci warned that it ‘vanishes into thin air if not varnished quickly.’ These days synthetic pigments provide a more constant alternative.

Despite its past uses, verdigris is a big problem in pinned insect collections. Nowadays stainless steel pins are used, but pins containing copper still remain in old collections and these react with air and insect fats. The more fatty the insect, the more verdigris tends to form and, if left, it can damage a specimen irreparably.

Comprising around five million or so insects, the Hope Entomological Collections here in the Museum take quite a bit of looking after. A few years ago a project to catalogue and conserve many of its butterfly and moth specimens was undertaken and the removal of verdigris and repining of insects was part of this.

With paint-making in mind, I asked that the beautiful, but problematic, substance be saved.  About three years on I finally got around to using the pigment, which I had also been adding to while photographing the collections.

I chose a variety of differently shaped moths to paint (most of the verdigris came from moths, so moths seemed the most apt subject). To narrow my options further I went for green moths. Some of the specimens I chose had verdigris on their pin, so I was able to take pigment and use it to paint the very specimens from which it came!

Katherine tested out the newly made verdigris paint in her sketchbook.

After a first failed attempt to make watercolour paint (during which pigment and water remained stubbornly separate due to the greasy insect fats still present), I tried again, this time using linseed oil to make oil paint – and it worked! Traditionally a flat bottomed tool called a muller was used to press pigment into the water or oil. Not having one of these, I used the flat end of a pestle and a mortar which did the trick.

A Miscellany of Moths, the finished verdigris painting.

The paint went surprisingly far and, following on from the 14 green moths, I plan to use up the remainder to paint beetles.

Katherine’s Miscellany of Moths painting can be seen on display in the Museum’s Community Case until 18th October.

Imitation game

Last month we had the pleasure of hosting artist and scientist Dr Immy Smith as part of her week-long takeover of @IAmSciArt on Twitter. Drawing inspiration from the Museum’s collections, Immy has created some beautiful paintings. Here she tells us a little more about her interests and work…

My current artwork is focused on crypsis and mimicry – the ways that animals and plants disguise themselves or pretend to be something they’re not. Cryptic camouflage helps animals to avoid being seen, often to help them catch prey – or to avoid becoming prey themselves! Mimicry is also often about trying not to get eaten: the harmless hornet moth, for example, mimics a stinging insect to deter predators. I use these themes to develop print art projects, and also public workshops to help people learn more about the ecology of cryptic animals.

Cryptic Cards by Immy Smith

In my arts practice I try to imagine how animals and plants might evolve to camouflage themselves on human-made materials, and what they might look like. Will we one day find moths adapted to hide on advertising hoardings, or beetles mimicking litter? I made an entire deck of Cryptic Cards as a response to this kind of question.

Another project I’m working on at the moment is called Emergent Crypsis. This is a collaboration with Norweigan generative artist Anders Hoff who makes art using algorithms executed by a computer. I’m imagining how creatures might adapt to an extreme example of human-made patterns – computer generated abstract images.

Violin Beetle (Mormolyce phyllodes) by Immy Smith

My work requires me to closely study many animals and plants, but how do I learn about all these species in order to draw their imaginary relatives? How do I make my art a convincing representation of how life might find ways to hide on human-made art?

One answer is of course, the internet. I’ve been lucky enough to find many wildlife photographers online who are kind enough to let me use their images as reference. But photographs alone are not always enough to get to know the fine details and defining characteristics of a species: the joints and articulations of small insects, for example, are best studied from specimens. And some species are rare, or even extinct, and it can be hard to find photographic a reference.

Leaf-footed Bug (Diactor bilineatus) by Immy Smith

This is where scientific collections come into the picture. The collections held in museums and other institutions are not only essential for scientists and scientific illustrators, they are also an invaluable resource for artists of many disciplines, science communicators, and educators of many kinds. In the collections at the Oxford University Museum of Natural History I can photograph and sketch leaf-mimicking insects, for example, that are native to the forests of South America which I may never visit. I can study in minute detail the articulation of beetles that are rarely seen, and which might be difficult to find – and irresponsible to collect – myself.

A display of terrestrial bugs (Heteroptera) in the Museum, including the Leaf-footed Bug painted by Immy Smith

Not only do I find specific species that I want to study in natural history collections, I often see new ones – animals I didn’t know about or hadn’t thought of drawing before. In the same week that I visited Oxford, I also made a trip to Herbarium RNG in Reading to study plant mimicry, and found similar inspiration there. I can channel all this into both aesthetic art destined for print and sciart workshops that communicate the wonders of insects or plants with the wider community.

Working on sciart projects and educational workshops helps me appreciate the multitude of ways in which collections benefit research and education. We must try to communicate the plethora of roles they play, and the host of ways they cross into our lives – whether through scientific research on insects pollinators of the crops we eat, or via a deck of cards made by someone like me for mainly recreational purposes. We must fight to protect scientific collections because they are a resource that benefits all of us as a society.