I first started making foraged plant-based inks in September 2019. I went foraging for the first time with my boyfriend in the Wissahickon Valley Park, where I collected goldenrod flowers. Goldenrod flowers make for a beautiful bright, yellow ink. Ink making, which is similar to dyeing, requires plant material, a large pot and a few jars; hot water and a few other simple, affordable ingredients to make. It can take hours or days to process, which is all dependent on what color/plant you’re working with. One of the easiest ways to get into making plant-based ink for the first time, is to collect avocado pits/skins and onion skins. Your food waste becomes ink to paint with! Below is my recipe for making avocado and onion ink, with a few additional tips on how to get different color variations.
PLANT MATERIALS
10-15 avocado pits
Avocado skins (2) per avocado
5 onions worth of skins (orange or yellow or both)
All these materials + 6-8 cups of water = 1 full medium mason jar (usually)
When I lived alone, it took me around 10-12 weeks to come up with that amount of food waste. Store your food waste in a plastic bag or a container and don’t worry if it gets a bit moldy. Wash the mold and debris off of your plant waste when you are ready to make ink.
Avocado pits make a pink/red color when used alone.
Avocado skins make an orange/tan color when used alone.
Onion skins (orange and yellow) make a yellow or orange color.
When the avocado pits and skins are combined (my preferred method), they make a warm yellow or light orange color. The color can also vary depending on how long you simmer your ink for, and if you choose to use a mordant/modifier or not. Using mordants and modifiers can really enhance your ink color. Note, if you cook any of the above on high heat for too long you get brown!
What’s a mordant or modifier? A mordant is iron, alum, tannin (found in nuts), or copper etc. These elements (usually natural metal salts) adhere your dye/ink to your paper or fabric, and they also change the chemical makeup of the dye/ink while you’re making it. I prefer to add mordants to my inks once they’re done processing during the jarring phase. Mordants and modifiers, like citric acid, baking soda and washing soda change the pH level in the water, transforming the color. Alum in avocado and onion ink makes the ink brighter (almost highlighter-yellow). Washing soda in avocado and onion ink makes it a deep, red-orange. If you add iron to avocado and onion ink it saddens the ink, making it turn darker, usually an earthy brown. I recommend using alum or washing soda for interesting color effects. By leaving the ink entirely additive free, it usually comes out as a medium to bold pink/orange color.
SUPPLIES
Alum powder (optional; it’s toxic, wear a mask when using and keep away from the face/eyes)
Washing soda powder (optional; keep away from face/eyes)
A large, deep stainless steel pot or aluminum pot (used for dye/ink making ONLY. Do not use your cookware!)
1-2 Medium or Large mason jars
1 additional mason jar to assist with filtering the ink
1 Large and 1 Small metal spoon
Small metal funnel set, paper coffee filters, a face mask and a few rubber bands
6-8 cups of filtered cold water (add more if the ink reduces too much)
Clove buds or wintergreen oil to add as a preservative
5-10 strips of paper to test ink on while processing and after
Gum Arabic in powder or liquid form, to use as a binder. You don’t really need a binder for avocado and onion ink. The tannins in the avocados help fix the color to the liquid. You can use Gum Arabic as a thickener.
PROCESS
Fill-up your stainless steel pot with water. Remember, as the ink simmers it will evaporate water. Too much water will make the ink transparent. Find a happy medium by experimentation. Add more water as needed.
Bring your water to a simmer on the stove (10-15 minutes).
Once the water is simmering, turn your heat to the lowest setting and add in your plant materials. Place the lid on top with a crack to let out some heat.
Let the plant materials heat slowly in the water for 30-45 minutes. Stir every 10-15 minutes. The longer the color cooks, the richer it will become. Your ink should be a rich pink/tan color in the pot. Use the paper strips to test the potency of your ink. You can do this as much as you like. I like to test my color every 20 minutes or so to see how it’s progressing.
After 2-hrs, remove the liquid from the plant material. Scoop out the plant materials and dispose of it in the compost bin. Pour the liquid into one or two of your medium or large mason jars.
Place a funnel with a coffee filter on top of a mason jar or place a coffee filter over the mouth of your mason jar, with a rubber band securing it. You want to strain as much plant material out of the liquid. This usually takes at least two strains to accomplish. I prefer to set my mason jar over a paper towel/cloth on my kitchen table. I pour the ink slowly over top of the coffee filter and let it strain for about 20-30 minutes at a time – by that point the coffee filter should be free of liquid. You’ll need to replace your coffee filters as you go, a fresh filter speeds up the straining process and creates less mess in the longer run. Do this at least twice, by straining into one jar as you pour from the other.
Once your ink is strained and settled, I recommend adding in a few scoops of gum arabic powder or a few drops of the liquid. The powder takes some effort to mix into the ink. Mix until you no longer have large white clumps. Some residue is fine. Mixing can take around 10-20 minutes or so.
(Optional) It’s now mordant/modifier time! You can add alum to turn your ink into a bright yellow or add washing soda to make it a red-orange color. You only need a spoon-full of each mordant to radically change its color. I like to add 2-3 spoonfuls per ink jar. Sprinkle the mordant into your ink jar and mix it in well with a small metal spoon. Avoid getting any substances in your eyes or mouth, it can cause irritation. Keep away from food, pets and children while you're mordanting your ink. Washing soda will bubble up like a dropped soda can so be careful — things can get a little messy! Grab test strips of paper and try out how the ink looks on the paper. Add more mordant/modifier to see what happens. There is no “right” or “perfect” color outcome.
If you like the color you have, finish the ink by adding clove buds (3-5) into the jar or (3-5) drops of wintergreen oil into the jar. This will preserve the ink and help keep it from growing mold. Handmade inks are living things, keep this in mind. They might change due to light, temperature conditions and age. If you see mold, remove it with a spoon or a paper towel. Mold usually sits on the surface. If I see mold forming, I’ll clean it away and then add in more preservatives. I re-jar my inks once a year, usually each fall when I’m in the midst of foraging and ink making season. This helps prolong the life and quality of the ink.
Label your ink (Name/Month/Year/Mordant/Modifier if used) and add it to your collection! I like to create an ink swatch at this time, on a spare piece of watercolor paper. I write down the same label details and brush ink across the paper. I add the swatch to my archive, to remember all the different types of ink I’ve made. It will also help you better understand how the inks react to time, light and air exposure. And now, your ink is ready for use!
Onion skins (left), avocado pits (center) and avocado skins (right)
Onion skins, avocado pits and avocado skins in pot simmering.
Filtering ink from the pot once the ink has cooled.
Testing color quality and mordant/modifier changes to inks.
Final ink color outcomes with modifiers added.