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anna bussot: ferruginous ink

Anna in her studio

Anna Bussot’s work has drawn much attention since the opening of our spring show at the end of March. Inspired by holidays spent in Scotland, where she gathered field trip sketches, photos and notes on her travels, Anna’s work clearly evokes the wild, rugged and untouched beauty of the Scottish Highlands. Her work goes beyond the confines of traditional landscaping, blurring the distinction between the imagined and real, somehow inviting the viewer to step inside the canvas; to explore further and immerse yourself in the newly charted territories and emotive worlds within. But how is this effect achieved?

infinite flow, glencoe - ink and gouache - anna bussot
55 x 46 cm

Part of what makes Anna’s work so otherworldly is her use of cartography combined with graphite, gouache and ferruginous ink (yes, it took us a few attempts to pronounce it too), amongst other materials. We were immediately intrigued by this particular type of ink and, wanting to know more, asked Anna to provide us with a bit of background information on this lesser well-known material. We also did a bit of digging ourselves.

Ferruginous. adj. Mid 17th century: from Latin ferrugo, ferrugin- ‘rust, dark red’ (from ferrum ‘iron’) + -ous. 
    1. Containing iron oxides or rust.
        1.1 Reddish brown; rust-coloured1


Ferruginous ink or Iron tannic ink (also known as Iron oak gall ink) is a purple-black or brown-black ink made from iron sulphates and tannic acids from vegetable sources. According to Wikipedia (the collective brain of the 21st century), it was thought to be the standard writing and drawing ink in Europe from about the 5th century to the 19th century, and remained in use well into the 20th century.

At its inception, ferruginous ink was widely used for documentation due to its indelible qualities in its purest form. However, it was not long before artists saw its potential, using it with brush, reed pen or quill. Rembrandt often used a rust-brown tone of the ink to capture first impressions and studies of his subjects. 

study sheet with three women and a boy - pen and ink - 
rembrandt - c.1638-39

The ink was traditionally prepared by adding some iron sulphate (feSO4) to a solution of tannic acid (C76H52046). The tannic acid was extracted from galls (growths caused by parasites laying eggs on trees) by either grinding them down into a powder, boiling them, or leaving them to ferment over a relatively long period of time until they were mouldy.2 Hence the alternative name Iron oak gall ink.

Anna first discovered the ferruginous ink in a master class on experimental techniques. She prepares her own mixture by taking the tannic acid from pomegranate extract before dissolving this, along with the sulphate, in distilled water before adding gum Arabic (acacia gume) as a binder. The effect of the ink is, as you can see below, rich and surprisingly versatile.

We asked Anna what she enjoyed about working with this particular media: “The flexibility of execution allows me to work both the emotional and the informative content. That is, to use the stains and also the lines...  And the variety of tones offered by the oxidation of iron, reminds me of the Scottish dark waters...”

Other examples of Anna’s work are currently on display in the gallery and can also be found under the artists section of this website. 


1. Anon. (2018). Oxford English Dictionary. [online] Oxford University Press. Available at: [Accessed 27th April 2018].
2. (2018). [online] Available at: [Accessed 1st May 2018].

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