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Materials as Relationship

a conversation with Carolyn Sweeney of Strata Ink

September, 2023

IG @strataink

CINA Hi, Carolyn. Thank you so much for taking the time to chat with me. Let’s start with where you are, who you are and what you do. 

CAROLYN Hi Cina. I'm in Portland, Oregon, United States. I have a BA in fine art, but I didn't learn all of this materials-based work during my formal studies. After I graduated I studied textiles at Oregon College of Art and Craft. I learned how to weave, spin, and use natural dyes. I realized then that I was the person who wanted to shear the sheep. I want to go all the way back in the process and the materials. I studied until I could work from a raw local fleece with local dyes and spin the yarn and weave whatever it was that I was trying to make.

But this work was very time-intensive. Once I had a kid, that kind of time investment wasn't viable. So, I went back to working on paper which is more transportable to the playground or wherever you're going. It’s kid friendly in that way, and kids can interact with it as well.

I took that natural dye knowledge and created my own inks with black walnuts from my backyard, and various other things I'd been growing in my garden. Later, I also got into minerals and making mineral watercolors and inks. I teach mineral watercolors, botanical inks, and lake pigments. I also make crayons that are made with soy wax and natural pigments. 

I started Strata Ink in 2020. I wanted a name that brought to mind process and geology. It’s similar to gathering knowledge, you know? We all accumulate layers and they build slowly into something visible. 

CINA Talk about the difference in using botanicals and minerals, why you choose one medium over the other and for which product?

CAROLYN I think of them as two sides of the same thing. When I am working with natural materials, they all come from the earth, but plants and minerals have different qualities. It’s as if one is an inhale and the other an exhale. They aren’t the same, but together they make a whole.  I use both plant and mineral color on paper and often in the same work. But the way of working with them feels different.

I started off working with plants. The process of making plant ink can be a lot like making tea, soaking a plant in water to extract the color. There are other ways to work with plant color, but this is the most direct and simple. Everybody who works with natural pigments works with them differently, which is one of the fun things about learning from other people. Everyone has their own methods.

With plants, you often get the color quickly, within an hour or 30 minutes of simmering, sometimes even ten minutes. Once the color is in the water you can put it right on the paper. It's ready to go. It's often very bright and vibrant, and it changes with different mordants like adding alum or iron. It changes with pH modifiers. It changes with the pH of your paper, even the sizing on your paper all have an impact on the color.

Plant color is nimble and light-footed and it's changing all the time. You can get many different colors from just one plant. And those colors are going to shift over time, both as they dry on the page and as they age. They're going to fade. Most plant color is not fully lightfast, meaning that the colors will change when exposed to UV light over time. It doesn't mean they disappear, but the vibrancy generally diminishes. The colors that they fade into can be very beautiful. Some of the plants are extremely fugitive, meaning the color doesn’t last long, like pokeberry. I have a bunch growing over my studio steps right now. It's completely taken over. This morning my partner looked out the door and he'd never seen those plants there. He was shocked. They're six feet tall, huge. And he asked me,” What is that? Where did that come from?” I told him, “Those are pokeberry, but they'll be gone soon, don't worry.” They can’t handle a freeze so they grow every summer and then die back over the winter. And that's how the color is too, with the pokeberries, not all plants. The pokeberries make this beautiful fluorescent pink, and then it changes within a few months to beige. It's so strong, such a potent pink. You can put it over charcoal and you're going to get a fluorescent pink. To me, that's worth it. And if its protected from UV light, like in a sketchbook it will last much longer. 

It's just like growing your own tomatoes. Of course, you can't eat them in January, fresh off the vine. But is that a reason to not grow them? No. You want to eat them in August. It's so worth it. And that's part of the joy. You wait all year for those months when you have them and they taste so good. Color can be the same. You wait all year for this color. You can put the berries in your freezer, to save for another season. It’s a time-based experience. 

So, I think even the less light-fast plant colors are worth exploring. And of course, there's some plant color that is quite lightfast. If you want more stable plant color, look to the tried and true dye plants. People have been seeking strong, stable color for a long time. 

In contrast, the minerals that I'm collecting are very stable. They’ve been exposed to the weather, the elements, the sun, the rain for many, many years. Some have been exposed for millions of years. They're not going to change. They're very solid and steady. Working with them reflects this. You need to grind them, wash them, maybe levigate them. It is all to create and sort out fine particles. After that you can make them into some sort of artist material with a binder so that those fine particles stay on your art surface. They're completely lightfast. But the colors are more subdued, more soft, earthy colors. So, it's just two different ways of working and I like to use them together. 

This painting on my table right now has oak gall ink in the background and red ochre and Maya blue pigments. Maya blue is a great bridge of plant and mineral color where you chemically bond plant indigo with a clay. And it's quite light fast. 

Probably my most asked question is, “What is an ink?” It's a very mysterious thing to people. You can mix dyes and pigments within an ink because it's wet. You can mix lake pigments and minerals. You can mix anything you want into your ink. It can all be together. That's one of the fun things about ink.

CINA Do you use plant pigments for your crayons?

CAROLYN Only indigo powder. For the crayons that I make for myself, I might use lake pigments. You can't use anything water-based, so no dyes could be in the crayons because the wax will not blend with water. All the material needs to be dry. Lake pigments are the best way to get plant color in a dry form. You need a fair amount of pigment for a good crayon and lake pigments are very labor-intensive to make. So it would not be economical to sell lake pigment crayons for me. I want to keep them affordable. But for yourself, of course, you can make them.

CINA Yes, I only use mineral pigments in my crayons. I’ve tried using lake pigments, but I do not find them to work as well with the wax. I also use an indigo pigment that we get from a coop in India. My co-founder Bethany was there to learn with them and it's a really high-quality indigo! It's the only plant material in my crayon recipe that mixes well. All of my other plant-based pigments just sink.

CAROLYN The indigo is somewhat hydrophobic. When you're using it as a pigment with a water-based binder, it can be challenging. So it makes sense that it blends well with the wax. I also use charcoal and that works well. 

Indigo is my favorite crayon. It's so beautiful. I love it. I did a series of drawings with the crayons this winter. Winter is usually when I get to actually do my own work and I did a series of drawings that were just with red ochre, indigo and graphite crayons. I only used three crayons.

CINA So you do still practice your own art?

CAROLYN Oh, yes, definitely. That's where this all comes from, these are the art supplies I want to use for myself. I have an artist website at where you can see my work. All of it is made with natural pigments.

One of my campaigns is to get people to do bigger swatches. Like when you sit down to swatch, you think, “Oh, I'll just try this one ink.” But just use a big piece of paper because inevitably you will end up trying other things and you never have enough space. I do it on nice paper because I want them to last. It becomes your personal reference library.

CINA Explain what “swatching” is for someone who might be reading this and doesn’t know.

CAROLYN Sure. Swatching is a big part of the natural color world and I think it's because most of us are learning how to use these natural materials that are unfamiliar. If you went to art school or made art at home, these are probably not the kind of materials you were using. You were likely using synthetic pigments. Swatching is just putting samples of color down on paper, trying out different variables and combinations. 

It's like learning a language. I’ve been learning by doing. I wanted to learn what plants around me make what colors and in what season. Does it matter when you harvest them? What kind of water do you have? What different things can you put with them? How do they combine together? I have all these questions and there's no answer other than to sit down and try it. Maybe you can find someone who's done something similar, but often not.

I'm really focused on what's abundant. Find out what's on your block, what's falling on the ground, what people are putting in their compost. What's invasive? I think you do go through this process of intense experimentation where you have no capacity for anything else and you're just swatching. Eventually, it calmed down for me and I started digging in deeper to a smaller set of plants. It may be that there's still other great plants out there, but I got hooked on a few and they're so interesting that I naturally want to go into those further. 

There are certain plants that I keep coming back to. They're readily available to me. They have great color. They have interesting qualities. And it's the same for minerals.

CINA How does that impact your sense of place, using colors from your own area?

CAROLYN So much! I walk my daughter to school and back and a lot of my plant foraging comes from those walks - just our path to school and back. I was excited when she started going to a new school this year because it gave me a new foraging route. It's almost like tracking in your neighborhood. You start to piece together clues about what's going on and seeing the seasons. I have my favorite buckthorn trees. I love working with privet and I looked for it for years. Not that hard, but I had it in my mind. It turns out my next-door neighbor has a huge privet hedge that is on the sidewalk. I walked by it for years before I noticed what it was.

CINA Do you always lake your plant inks?

CAROLYN No, not always. Mostly I just use them as a concentrated dye. In my classes, I want to use local plants. Of course, I have to test it all before I can teach. They are so beautiful, and they're as light-fast as a textile mordanted with alum and naturally dyed. They're shelf-stable once the pigments are dry. But it is a lot of work to make them. 

CINA What are your thoughts on the ethics of “using" nature for our own art purposes? 

CAROLYN That's an interesting question. I don’t think of my art practice as “using” nature. I think of it as being in relationship with nature. We are all completely dependent on nature for our survival, for food, water, and shelter. It’s no different for our creative practices. 

My teaching revolves around encouraging people to have an intentional relationship with the natural world as a part of their art practice.

We aren’t only looking at the natural world, we are physically interacting with it.

Using natural materials has influenced my own art practice a lot. I don't do much representational work at the moment. I don’t want to corral these materials into creating my vision. I think of it more as a collaboration. I wouldn't sit down and paint a specific image that didn't feel related to the plants and minerals I’m working with.

My daughter and I have this conversation because her work is all about story. It's her vision of a story and a character and it's very specific. I think for that kind of work, it makes sense to use what I call anonymous art supplies-art supplies that you just want to do what you expect and behave and be predictable and serve your function because you have a vision and that's what you're doing. 

That doesn't make sense for me when I’m working with natural art materials. I hear people talk about how they want to be more sustainable in their art practice so they’re going to switch over to natural art supplies. I don't think it's a one for one substitution, a mineral green for a synthetic green for instance. For me, it's all about relationship. It's no longer just me alone on the page. It's me and these plants and minerals. For me, that is so exciting and so much less lonely.

I like to forage in heavily impacted areas, like the side of a highway, so that my personal impact is very small. That's a sense of place, too. That's a place that I adore. This side of the highway place is one of my favorite places on the planet, and it never would have been if I wasn’t looking for earth color. I drove by it for 20 years before I ever realized that there's a bunch of red ochre there, and a bunch of other colors too. I know from walking it. Looking for color gives you these special places that you wouldn't have had a reason to interact with.

So, I think being in relationship with these materials is a good thing. That's being human, to me. We're here as members of the community of the Earth. Use and reciprocation is part of that whole process.

CINA I've been thinking about the idea of conservation. I wonder if on some level we are participating in a degree of conservation by bringing in some of those natural elements, incorporating them into a communication that goes out to others in new ways, which might help people connect to the natural world in new ways. This would, by extension, hopefully inspire them to care for the natural world in new ways.

CAROLYN Absolutely. I think that's very real if you're making work that connects with people and it has that element in it. For me, I can't talk about the work without talking about my relationship to the natural world. I don’t just happen to be using this red ochre from Oregon. To me, that's so much a part of the process that it is going to be a big part of the work.

As humans, we are using the natural world and we have to come to terms with that. That is what it is to be human. It's what it is to be alive. Everyone is using resources. So, how do we use them in a way that's respectful? How do we use them in a way that's in keeping with their nature and isn't degrading them or dishonoring the things and people around us or ourselves or the process?

I definitely talk about ethical foraging in every class and about the fact that this is native land that I'm living on. I'm a guest here, and how do I relate to that? I donate 12% of all the sales of ink to a local Native-run non-profit organization because the pigment is mostly foraged from here in Oregon. 

If we're buying everything from a store, it's easy to skirt around the fact that we are consuming natural resources. When you're getting out on the land and you're really getting your hands in it, you can't avoid that fact anymore. The fact that you're taking something from the Earth, the fact that you're using land that doesn't belong to you, you really have to come face to face with these things. To me, that's very healthy. I don't think there's any right answer. I think the important part is that you're thinking about it. How are you going to be in right relationship with the earth and everyone who shares it? 

CINA Right, which all goes back to a sense of place. Have you noticed that getting involved in the natural and making art materials shifted your sense of place, with being rooted there? Has it impacted you in any new ways?

CAROLYN Yes, I would say mostly in my art practice. I already felt pretty rooted here and have different places that feel special to me, like that place on the side of the highway. I drove by that place, I just didn't have a relationship with that road or that particular part of the highway. So, it’s given me different places that I have relationship with, now.

I really enjoy my plant practice being so neighborhood-based, where I have this mental map of the neighborhood, of what and where I can forage, what's ready right now, and which way to walk. Often, I'll walk my daughter on a different route than I did the day before so I can see a different set of plants. Then, that really ties into your neighbors, too, because a lot of my foraging is not in my own yard. It's in my neighbor's yard. I'll leave notes in people's mailboxes to say, “Hey, I see you have this. Can I have some of that?” Usually, what I want is their fading flowers. I'll put my phone number and say, “Hey, can I have some of this?” Pretty much everybody says, “Yes.” Nobody's been unhappy about me deadheading their flowers.

That's a fun way to get to know your neighbors and your neighborhood as a place that's very specific. If I went 50 blocks north in Portland, I wouldn't know where to forage because I know a little 20-block radius around my house.

CINA So, the purpose of what we're doing with Wild Arts Learning is getting people connected to nature through the arts. You’ve shared how that manifests for your art, but can you expand a bit on how that manifests in your teaching?

CAROLYN In almost every class, I hear, “I never thought about that" or "I've never noticed that plant.” I just volunteered to take a hiking group out for mineral foraging. Over the two or three hours we were looking at rocks and clay on a beach people were saying, “I never would have noticed that and now I do!”. I've told so many people about buckthorn berries and tell them, “Look for what's at your feet, they’ll be dried up on the sidewalk,” and you can see their eyes light up like, “Oh, okay, that's a new thing to look for.”

It's all right there. It's just about noticing. It's about what we're looking for. So to me, that's the really exciting thing, that there’s all this color surrounding us at all times. We're just not aware of it, so we think we need to go buy it. And maybe you do if your practice is like that, if that's what you're working on. But there's such abundance in nature. That's a lot of what I want to communicate with people, that there's so much abundance around us. If you're able to focus on that, you never need to be lonely, again. There's all this material that can become relationships, that you're surrounded by, you know? You're not alone. Ever.

CINA Wow. Nice. Okay. I've kept you for a really long time, so I'm going to wrap it up with this last idea: specifically getting kids connected to nature through the arts and why that is important.

CAROLYN Well, most of my experiences are with my own daughter, who's almost 15. She walks to school every day and part of what she does is snack on the way on whatever is out. We have a lot of linden trees which are not native, but we make tea out of them, so she'll snack on that. None of her friends know what she's doing. It's just from walking around with me. You don't have to be snacking, but just that feeling of connection as you're moving through space to me is really helpful.

To me, that's how our brains evolved to be in that kind of space and to be taking in that kind of information and stimuli. Not everybody feels safe to be out in the wilderness, or feels like they have the skills to do that. So, part of the work is to help children, and even adults, feel like they can be out there, whatever the barriers are for them. There's transportation. There's, personal safety. Then, there’s a lack of confidence in being out in a wild space. It’s all really important.

We don’t need to go to the wilderness to connect to nature. It can be a park, it can be just walking on your street. That is so healing. You may have access to a resource that's near you, but you may not be tuned into it.

CINA How do you recommend people get out and get started?

CAROLYN You can start really small and close to wherever you're living. Look outside your door. Start noticing the plants around you. Drawing them is a great way to notice because you start to learn the leaf shapes and the patterns. Plant life is its own language, its own visual language, and your eyes start to identify the differences between the different leaf shapes over time. You start to know what plants you're looking at, what’s abundant and when, and what's happening around you. If you're looking for color, you can google whatever plant it is. Once you figure out what plants you have, there's a lot of information about natural dye (much more than there is for things like ink or working on paper with those plants). Making ink will be a similar range of colors to natural dyes, so you can start there.

Start noticing what's on the ground and on the sidewalk. Look for stains from things like walnut hulls. Plants that stain will give color. 

In winter, you might say, “Well, there's nothing to look at.” But twigs can make great color. Birch twigs and fruit tree twigs all make beautiful colors. So it doesn't have to be limited to the season where the leaves and flowers are out. Windfall is great after the storms. When storms come through and you have branches on the ground, snip them into little pieces, throw them in a pot, simmer them and see what happens.

Carolyn Sweeney

It may take a while, but just leave them. And a lot of them smell really good. All the fruit tree twigs smell like the fruit, so that's nice. If you're out pruning your garden, you can simmer up what you pruned and see what happens.

Experimentation is the heart of it all. If you're willing to try things, you're going to make discoveries. It’s just a matter of time and attention. The materials are all around you, at all times.

CINA Time and attention. That's so true. Okay, Carolyn. Thank you so much for taking the time to do this. I look forward to connecting more in the future!


For more from Carolyn and to learn about Strata Ink and her art, visit and


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