Hi, I'm Caitlin

I’m a practicing artist located in Massachusetts focusing in traditional creative approaches including stained glass, ceramics, and material creation.

This blog covers my process, interests, and inspirations as research becomes a larger part of my practice.

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The Saint as Cephalophore

Bucephalus and His Tail

The Mystical Unicorn Hunt of Saint Guinefort

Saint Mermaid

The Dante Stones of Siena

The Miracle of Saint Guinefort from The Hours of Henry VIII

The Suffrage of St. Guinefort From the Hours of Catherine of Cleves

The Apotheosis of Saint Guinefort

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caitlinfitzgeraldart

Most of my modern day depictions of St. Guinefort

Are we done with winter yet? An additional 14" aft

New ceramic piece. I’ve been playing around with

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A newer cup, completed over the winter. Inspired

Small tansy painted panel, with kokomo textured gl

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January 2026 has been an absolute beast, probably

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Adventures in Ink Making

"...the dwarfs found out how to turn lead into gold by doing it the hard way. The difference between that and the easy way is that the hard way works."

Terry Pratchett

The Truth

When I was a kid, I loved alchemy. Or, more importantly, I loved the illustrations (of which you will find many if you follow the previous link to Occultopedia – my old teenage stomping ground for all the weird things that delighted my mind). Pictures and paintings with hidden messages and depths of understanding you had to hunt for to discern seemed infinitely fascinating to me. Plus it featured all the things I already loved – monsters, dragons, astrology, weird symbols and stuff like that. Is it any wonder Symbolism would become one of my favorite types of art?

Green Lion Devouring the Sun — A common alchemical image, the green lion devouring the sun is thought by some to embody the process by which green vitriol (the lion) dissolves or “devours” all metals except for gold (the sun). Most images in alchemy have multiple meanings and interpretations.

The basic principal to alchemy was to discover the fountain of youth and how to transmute lesser metals into gold, bonus points if you get them both together in the form of the Philosopher’s Stone.

Practiced by Sir Isaac Newton, referenced in Goethe’s Faust, the basis of Hermeticism – the reach of alchemy is far and its influence can be found in surprising places well beyond the few mentioned here.

I could go on, but the point of this post is to segue into a specific topic where art and alchemy intersect: iron gall ink.

Some weeks back I attended a class run by artist Thomas Little that was hosted by the Académie Gnostique, whose work is a delight to look at. I was initially caught by the title of “The Alchemical Artist Palette” and then sold by the mention of iron based inks. I’ve been yearning for a kiln and the ability to paint on stained glass again, which uses lead and iron based pigments, so I was intrigued at the prospect of perhaps learning a little about how I could make my own glass pigments someday (maybe, hopefully).

Supplies Used for Inkmaking — Green and Blue vitriol (iron sulfate and copper sulfate) came from the class. The gum arabic, which has a million uses, was purchased online.

The class was great, and everyone left with some goodies to try pigment production of their own at home. I bored everyone back home around me with accounts of all the fascinating details for the next two weeks and then tried my hand at a few iron based ink recipes.

So, I had my basic recipe: green vitriol (or iron sulfate), crushed oak galls, and gum arabic*.

Oak Galls on an oak leaf. — Oak Galls as they appear on an oak leaf.

But wait, what are oak galls? As the name implies, they appear on oak trees and are caused by a gall wasp laying eggs on a developing leaf bud. The gall forms, in exact terms not really known, but it feeds and protects the wasps as a kind of egg until they emerge as adults. Weirder still, gall wasps are part parthenogenetic in their reproduction cycles – one year all female wasps lay eggs that produce the next generation, and another year both male and females are produced and mate. Some species also use other plants to incubate their eggs. It’s not clear to me if galls are harvested once their hosts have left, but I can’t imagine wasps are spared.

The idea is a solution high in tannins, which interacts with the green vitriol to create the ink. Well, tannins are everywhere in nature. After some weird sidetracks into blackwater aquarium websites I found some evidence that Magnolia leaves and pods may contain a decent amount of tannins. Since my yard is littered with both, I figured it was worth a shot. One container I filled with crushed leaves and water (this was later discarded as it grew a funky odor), the other with crushed Magnolia seed pods, water, and acetone (after finding some vague evidence citing it helps extract tannins in some way). But, I wanted to try the traditional method as well.

Brewing tannin mixture — My home made tannin mixture, which as of this writing is still steeping. I will test it in a few months to see the kind of ink it produces, likely after reducing it a bit by boiling first.

A quick trip to on the internet and I had ordered up additional iron sulfate (green vitriol), oak gallnut extract, and cutch extract (it said it had a high tannin content so I was curious if it would make a more humane replacement for oak galls). Links to materials used are at the bottom of this post for those of you who would like to try and make this ink at home.

So, on an appropriate Halloween evening I decided to try the first of two recipes I had selected from the Iron Gall Ink website:

Completed Iron Gall Ink — My completed batch of Iron Gall Ink.

Recipe 2: ink prepared by boiling galls (preparation time: 4-5 hours)

Ure’s Tannin Ink Galls – 18 parts by weight
Ferrous Sulfate (Our Green Vitriol/Iron Sulfate) – 8 parts by weight
Gum (Gum Arabic in my case) – 7 parts by weight
Water – 145 parts by weight

“Add 130 of the water to the powdered galls in a pan, and boil with constant stirring, to prevent the ink from burning, for two hours, adding water little by little at intervals to replace that lost by evaporation. The decoction is then allowed to cool, and filtered…While the filtration is proceeding we dissolve the vitriol and gum in the remaining 15 parts of water, and pour the solution into the filtrate. The ink does not develop its full blackness at once…”

I had gathered about a water-bottle full of rainwater from a drawer sitting in my yard on it’s way to the dump (my yard is a bit of a mess as the garage is getting torn up) and filtered it through a paper towel after reading that rainwater or distilled water were the best options since water from pipes could contain contaminants such as chlorine that could impact the final outcome as well as trace minerals (not something I had known when creating my magnolia tannin mixes – oh well). I weighed both the powdered gall I had ordered and the rainwater with a gram scale (130 grams by weight of water is NOT a lot). I measured an additional 1.5 cups after reading through the website notes that an additional 350 milliliters of water (by volume) was added through the boiling process to keep it from completely evaporating. I boiled the mixture for a little over an hour and a half, once I had run out of the additional rainwater, and set it to the side to cool.

After cooling I filtered the tannin through a paper towel. It had taken on a rich brown tone by this point. I followed the remainder of the recipe by combining 145 grams (by weight) of water to 7 grams gum and 8 grams iron sulfate. The liquid created was a dark yellow and very viscous. I added this to the tannin mix and it almost instantly turned a rich black. However, the gum arabic remained clumpy in the mixture. I stirred as best I could and then strained the final ink one more time through a paper towel (definitely will use cheesecloth next time). I tried a few strokes and watched as the ink became even darker on the page.

By the next day the mix had darkened even more, and as it has sat it seems to have reached full blackness. It no longer changes color on the paper and is a cool black that washes to a purplish-blue when diluted. I personally feel there is a bit too much gum arabic in the recipe – it leaves a very shiny residue on paper where I prefer more of a matte finish- but I am thrilled to have a working bottle of ink.

Close up of ink after sitting a day — After a day the ink had taken on a permanently purplish-black tone and no longer darkened on the page after use.

A few notes as I have continued to use it. I initially opted for a glass pen but admit I am not very familiar with them. I managed to immediately create a small chip in mine. Since then I have used either a brush or ancient dip pen and found both of those very suitable.

It’s particularly nice on Yupo paper as it flows beautifully. Paper with a tooth to it can be tricky but I put that more down to the pen. I did add a small amount of wine and a bit of extra water to the ink to both help it flow better and inhibit mold. It will be interesting to see how acidic the ink turns out to be over the years.

I do still plan to try the fermented recipe but have not gotten around to setting up the initial gall powder fermentation. I’d also love to try my hand at making my own green vitriol with a sulphuric acid bath and some railroad nails (I live close to a train yard and they are literally EVERYWHERE). But that experiment would involve more caustic materials than the ones experimented with here. So for now I’ll enjoy this rich ink and the sense of pride that comes with producing your own art materials (who knew how satisfying that could be? I’ve already bought some indigo seeds with plans of experimenting with them).

Line drawing of a cat — A quick study of my ever-mischievous cat, Alfie, in the finished Iron Gall Ink.

If you’re not quite as enticed by attempting to play the role of ScientArtist (as I am obnoxiously calling it) but are still interested in this historic ink there are plenty of sellers out their, particularly on Etsy, offering classic gall ink for you to try – many even recreate favorite personal recipes from figures such as Jane Austen.

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Citations:

*“Get More from a Rural Pen Inkworks on Patreon.” Patreon, 30 May 2019, www.patreon.com/aruralpen. Accessed 9 June 2025.

**Reissland, Birgit, and Frank Ligterink. “The Iron Gall Ink Website.” Irongallink.org, Rijksdienst voor het Cultureel Efrgoed, 13 Feb. 2011, www.irongallink.org/igi_indexc33a.html.