In the spirit of John Green’s book of the same title, our theme for the month of October is “the Anthropocene reviewed.” Writers were asked to review and rate some facet of human experience on a five-star scale.

I would make the worst spy ever.

And yet…

There is nothing I love more than a mystery that involves invisible inks.

I love invisible ink.

I love the history of invisible ink, one of the first recipes being traced to the writings of Pliny the Elder in the first century, who was using a kind of plant milk.

I love the inks of the Word War I era, where in 1917 papers were written by the Office of Naval Intelligence (the CIA didn’t exist yet, so all hail the spies of TOoNI) using this now-familiar recipe of espionage—the secret ink messages revealed by fire or acid, with “F” or “A” being hidden on the page to alert the reader on how to activate the ink. The recipe, after being perfected by the then-fifteen-year old FBI in 1976, consisted of:

I love the outrageous ink commissioned by George Washington himself, developed by Sir James Jay, a patriot who dabbled in chemistry. Jay made a “special formulated reagent,” only accessible between George Washington, Major Benjamin Tallmadge (the Continental Army’s spymaster), and the famous Culper Spy Ring. All of the men privy to this ink would write boring letters on top of their top-secret messages, storing the ink solution in shaving gear, hollowed-out soap cakes, and hair brushes, or dipped matchsticks in it to use later as a writing utensil once dry.

The history of inks with ephemeral or espionage-esque qualities is long, full of slow iterative progresses and failed attempts. Mary Queen of Scots thought she was killing it with her invisible ink formula she used to communicate with the Catholic church while under house arrest, only to find out Lord Walsingham (the jerk) had been breaking her codes all along, and helped seal her death on February 8, 1587.

Early German spies in London used citrus juice to communicate with their spymasters, until Mabel Beatrice Elliot discovered the messages by heating up a letter, and by herself unmasked no less than eleven spies, all of whom were executed in the Tower of London in 1915. In the meantime, the Allies were still using milk and lemon juice while the German Army got creative after their London bust by using disassembled laxatives, and therefore able to pass their ink off as common medicines much to the disgust and disregard of the Allies’ soldiers. (“Those German soldiers must have the most persistent intestinal issues.”)

Inks, up until major developments in UV color protection in the 1950s, naturally had some fugitive qualities—fugitive meaning fading or disappearing when exposed to light—unable to be activated again like the classified TOoNI recipes.

Throughout history, natural sources made art and writing accessible, with the caveat of not being permanent.

Following historical trends in research, when there is a crisis, we fall back on these natural sources once again despite advances in printing and synthetic inks: the Revolutionary War, the Civil War, World War I, and for me, the first 2020 lockdown.

I didn’t bring home my canvas or paints from the painting class I was desperately trying to pass despite the chaos. With stores closing, grocery shopping became a big enough challenge on its own. Being picky about my paints suddenly wasn’t an option.

So, I made my own ink out of blueberries. It took me weeks to perfect, even longer to paint. Then, after a year, the blueberry ink painting was gone, just a faint brown outline where there used to be purple.

You would think that would have cured my experimentation with botanical inks.

But that year I made blueberry ink again. Then wild blackberry. Then a whole summer’s worth of natural inks. Two years later, I not only passed my painting class, but became an illustrator who at the heart of my practice lies my natural ink collection.

My favorite, most aggravating, most dangerous ink I work with? Pokeweed. In Michigan, pokeweed plants appear in wooded areas, just three or four feet high, with long, tubular pink stems. By September, those stems will be full of dark purple berries that produce the most brilliant pink ink.

Soldiers in both the Revolutionary War and Civil War, desperate to get messages home to their families, would forage pokeweed berries (aka pokeberries) for ink to write to loved ones.

Picture this: soldiers trusting this ink that it will stay visible long enough to make it home. Soldiers with their fingertips dyed pink from foraging, their soldier’s uniforms speckled with magenta drops, their notebooks filled with pink reminders and pink prayers. But it’s not without risk: the seeds and outer skin are toxic, the juice inside is quick to stain, and without a good place to wash your hands afterwards, one could end up with awful stomach cramps if toxins are ingested. One more thing to die of in a ruthless, bloody war: beautiful magenta ink on a love letter.

All pokeberry-stained love letters left from those wars are gone now; their messages, if stored right, survived the travel to its recipient but most likely not through the rest of the year, let alone to present day.

I still struggle with the impermanence of my natural ink work. I won’t have intact original pieces for an exhibition someday. Any work I hang up is likely to fade away within a few years if it’s exposed to light. I fight mold in my inks everyday, and chemical reactions that make color choices unpredictable.

And yet?

I don’t wish immortality on anyone, or anything, the more I think of it. The memory of loved ones is the only place those soldier letters live; I trust my audience to do the same with my work. And maybe I wax poetic when I say that whenever I walk away from an illustration smelling worse than Pliny’s milk concoction, with my fingertips tinted pink like a soldier, I feel as though time isn’t an enemy of these ephemeral expressions of love. Not really. Not as long as we share the burden and gift of remembering.

So despite all the laxative confusion, and the jerk Lord Walsingham, and the lost first-person history and pain of those wars—I give invisible inks (and inks that will eventually be invisible) 5 out of 5 stars.


Author’s Note: The recipe for pokeberry ink remains the same today, though there’s a good chance soldiers were using the juice straight from the berry—puncture the skin, and you have a very, very small ink well.

  1. Begin with approximately one cup of pokeberries. Smash them into pulp by (gloved) hand or using a mortar and pestle, or a smooth rock and a bowl. Strain the pulp, using cheesecloth or a trouser sock, into a bowl.
  2. Into the bowl, add ½ teaspoon salt and ½ teaspoon vinegar, and stir. The vinegar to help the ink retain its color, and the salt to keep it from molding too quickly.
  3. Collect this mixture in a glass storage jar, and store in a cool, dry place.

Happy pokeberry ink-making!



A Southern Recipe for Natural Ink,” New York Times

Natural Colorants: Historical, Processing and Sustainable Prospects,” National Library of Medicine

Pokeweed – today an unwanted plant, in 1776 the ink of freedom,” WHYY

Poke Plant an Unsung War Hero,” The Atlantic Journal Constitution

Man Knowledge: The History of Invisible Ink,” The Art of Manliness

The Messy History of Invisible Ink,” The Pen Company

Berry Ink & Quill Pens,” The Vinegar Institute


  1. Hannah Riffell

    I know we were supposed to take inspiration from “The Anthropocene Reviewed,” but you just one-upped John Green on Crash Course History 🙂 What a marvelous retelling of history!

  2. Geneva Langeland

    My sister and I had a blast “painting” our wooden swingset with pokeberries when we were little. Guess we got lucky avoiding the stomach cramps!


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