Failing Upward: Eco-friendly Sculptural Materials Research

by Kathy Bussert-Webb

Discover the innovative journey of eco-artist Kathy Bussert-Webb as she explores the challenges and breakthroughs in creating sustainable sculptural materials. This article documents her hands-on experiments with hempcrete, vegan leather, Roman cement, kombucha scoby art, lime stucco putty, and a proprietary organic sealer. Through a process marked by both setbacks and creative solutions, Bussert-Webb shares practical recipes, lessons learned, and the importance of persistence and adaptability in eco-friendly artmaking. Readers will gain insight into material research that bridges art, chemistry, and environmental ethics, offering inspiration for artists and makers seeking greener alternatives in their own practices.

Failing Upward: Eco-friendly Sculptural Materials by Kathy Bussert-Webb, PhD, MFA To cite: Bussert-Webb, K. (2026). Failing Upward: Eco-friendly Sculptural Materials. Zenodo. https://doi.org/10.5281/zenodo.19747449 (Published on March 29, 2026, revised April 24, 2026)

Introduction

I am an eco-artist; I try to use materials and processes that do not harm nature. In Seattle I find objects from nature respectfully, but I could not bring these things into Canada or the USA for my artist residency at Studio H Canada International Artist Residency and my pop-up solo exhibition at Arc.Hive Artist-run Center; both occurred in Victoria, British Columbia, Canada, in March 2026. This report focuses on my failures and successes in making hempcrete (bio-composite material) vegan leather from sawdust, Roman cement from volcanic ash, dried kombucha scoby art, lime stucco putty as a cement coating, and a proprietary sealer I created for plaster and papier/fabric mâché. The eight images in this report are documentation of my original sculpture and material research. The formulas I provided in this report are conceptual and may require further development. I base the measurements and ingredients on my previous attempts using recipes I found on the Internet for hempcrete, vegan leather, and Roman cement. It is best to make a small batch and let it cure so one can adjust ingredients and proportions and not waste resources.

Hempcrete

Because my practice focuses on using eco-friendly materials for sculpture, I searched for a lightweight material that would satisfy US and Canadian custom laws but would not harm the environment. I decided to make a product from hemp, a natural fiber from the inner woody core of a hemp plant, which one may buy for animal bedding. The hurd or shiv is chopped and then one adds lime and water and then pours the mixture into a mold to cure and to make a lightweight composite, resistant to mold and fire. I tried two recipes for hempcrete to make reductive, abstract sculptures (ones I could carve to create shapes). While I learned, I had no success. I realized later that these formulas were for housing insulation, and I could not find any instructions online for fine art sculpture.

Figure 1 shows my failed hempcrete and vegan leather for different sculptures I intended; after this hempcrete section, I focus on vegan leather. My first batch of hempcrete blocks in November 2025 were like granola, not firm at all. In early December 2025 I made a second batch, reducing the hempcrete from 75% in the first recipe to 50% in the second. However, four months later (late March 2026), the blocks did not bind together well. With little effort, one could take the blocks apart. Hempcrete is great for housing insulation, but it does not bind well for additive or reductive sculpture, unless one alters the ingredients and decreases the ratio of hemp to binder significantly. I thought of using hempcrete for sculpture after reading an article about Yasmin Bawa, a Berlin artist who makes abstract sculptures from hemp the size of adult torsos; please see https://www.yasminbawa.com and Lampoon Magazine Nov 3 2025.

However, all was not lost. For Figure 2 (New Beginnings), I used about four cups of hempcrete flakes under a thin layer of plaster; I used the lightweight hempcrete fragments to decrease weight, as this was a wall-mounted sculpture for my solo exhibition. I read online that hemp can be an aggregate for plaster and cement. Gravel is another aggregate, but gravel would add too much weight to my wall sculpture. Thus, the female sculpture in Figure 2 is about 75% hempcrete flakes (from a failed hempcrete block) and 25% plaster. The aluminum mold, which I bought at a thrift store, appears to be what one would see beside public toilet entrances for women. I kept the hemp and plaster mixture in the aluminum form to make the piece long lasting, as plaster can chip and crack if it is not encased.

In Figure 2, one can also see my proprietary formula for a sealer, which is perfect for a top layer of papier mâché, fabric mâché, to coat plaster. The sealer I created can hide imperfections and it creates an organic look for sculptures. Since the marble apple I used was heavy (from a 2010 teaching award I received), I made a large indentation in the hemp before I poured the plaster on top. I had the apple touch the left side of the aluminum mold to strengthen the bond physically, since I intended this as a wall-mounted piece, as one would expect to see on the outside wall of a roadside toilet. Normally I use only natural pigments, but I did coat the lava rock with acrylic paint because it was grey; I wanted the rock to be black for visual contrast and symbolism, and I knew the pigment would run if a collector bought it and got water or a damp rag on the sculpture later. Thus, I must balance my ecological ethics with what works, especially if I buy and use a tiny quantity of something like acrylic paint. Additionally, I shop regularly at an art thrift store in Seattle (Seattle Recreative), which lessens the environmental impact.

If I attempt eco-friendly hempcrete again, this would be the formula (no guarantee):

Hempcrete Ingredients
1.5 parts hydrated lime for masonry – type S (calcium hydroxide) – slacked lime putty stucco is stronger.
.5 part marble dust (calcium carbonate)
.5 part volcanic ash (pumicite, pozzolana – volcanic ash for poultry dust might work)
1 part hemp hurd (animal bedding) chopped in a blender for several minutes, then moistened with water
.25 part water or a little more (The five-ingredient mixture should not be soupy)

Directions
Wear plastic gloves and a face mask to protect one’s skin and lungs. Mix the first three ingredients, then mix in the pre-moistened hemp and water. Pour the mixture into a plastic-lined cardboard box with enough mixture to form a binding for reductive sculpture. The mixture should be at least 3” (7.62 cm) in any direction. Tamp down the mixture in the mold. After a day, cut off the box sides and slide the block gently onto a cotton-lined shelf. The hempcrete cures better when exposed to air and when no plastic is under it. Cure the block on the shelf in a well-ventilated and shaded place from 10-25 degrees Celsius (50-77 degrees Fahrenheit). The humidity should be 50% to 70%. Do not move the block for a month. Hydraulic lime works better for hempcrete sculptures, but hydrated lime has a lower firing temperature and thus emits less carbon dioxide. Also, hydrated lime reabsorbs more carbon dioxide than hydraulic lime; regardless, either one is less environmentally harmful than Portland Cement (Diaz-Basteris, Sacramento Rivero, & Menéndez, 2022). I used hydrated lime (type S for masonry) instead of hydraulic lime because of ecological factors).

Vegan Leather

I tried two recipes for vegan leather to no avail. Sawdust mixtures with other wood will not work. I needed pine sawdust because of its tooth, pitch, and resin, but I could not find a friend or local business that had it, so I bought pine shavings. I used my art blender and then my art coffee grinder to make the shavings finer, but the material would not break down. I will look for a used non-electric corn grinder for art purposes only or will save my pine sawdust when I saw plywood. The product I created took a week to dry, was inflexible, and the shavings were unfortunately visible (Figure 1). My vegan leather attempts looked nothing like the sleek vegan leather dress I saw in the article by David Cabra (no date). Also, I did not mix the sodium alginate well; one can see clumps of sodium alginate in my second attempt (Figure 1).

This formula might work; the revision is based on what I learned the first two times:

Vegan Leather Ingredients
3 parts near-boiling water
1/8 part sodium alginate (sargassum seaweed – not kelp)
1/32 part soybean oil or olive oil (plasticizer, softener)
1/32 part glycerin (plasticizer, softener)
1 part pine saw dust (must be fine like flour)

Directions
Wear a face mask and take care with the scalding water. Stir the sodium alginate into some of the hot water, then add this mixture to the remaining water in a blender with lid. Stop frequently to scrap the sides and bottom of the blender. Mix in the oil and glycerin. In a bowl, add the saw dust little by little. Pour thinly onto wax paper. Cover with wax paper and roll thinly with a rolling pin. Take off the top wax paper. Do not move it until it is dry.

Concrete and Limestone

I wanted to make aerated cement (aircrete) with whipped dish soap, but I could not use Portland Cement ethically. It causes about 8-10% carbon dioxide emissions because limestone and clay must be heated to elevated temperatures to make this cement (Jalal, Srivastava, Tiwari, 2025; Diaz-Basters, Sacramento Rivero, & Menéndez, 2022). Looking for an eco-alternative, I found Camacho’s (2024) Scientific American article, which mentioned C-Crete Technologies. This California company wanted $200 for ground shipping, excluding the material cost. Since this was not financially viable for me, I bought RapidSet Cement All because it has low environmental impact or damage. I tried additive sculpture, putting the RapidSet powder and water mixture on my armature. The wet cement would not stay put and kept sloughing off the armature, even horizontally.

I then saw Facebook posts of people creating flowerpots with cement and old towels. Upcycling materials would tap into my found-object practice, and the fabric strengthens the cement. Thus, I applied cement-coated fabric to a sculpture’s armature and created what I dub Fabric Cement for Fine Art Sculpture. This process is like papier mâché because one is using a binding agent (e.g., cement, PVA glue, or starch) with fabric or paper. One can see how I used a cotton mop head and cement for this sculpture’s base in Figure 3. (I wrapped the mop strands around wires to strengthen them because I wanted the bowl to look more like a nest in which the bird woman rested.)

After trial and error with RapidSet, I searched for a chemically compatible coating for my cured cement; I bought lime putty stucco from the U.S. Heritage Group (Chicago) because I got kidnapped in Chicago as age 18, and my exhibition was about me releasing and healing from traumas. Thus, natural limestone was perfect metaphorically because it softens harsh cement. Also white symbolizes cleansing, and my exhibition (Letting Go) focused on my inner healing. I had to make the cement rough by making scrapes everywhere with a dental tool so it would dry with tooth; this would allow the limestone coatings to bond to the cement. Although lime putty stucco is natural, it is caustic when it is uncured (rough on one’s skin and eyes). My fingers were like sandpaper as I drafted this report, even though I wore gloves most of the time. One would assume that the putty would be like clay, but it was not. Instead, I painted it on a sculpture in several layers with a brush and built up the limestone coatings so a sculpture would not have fissures or chips later.

For Figure 4 (A Part of Me), I created durable “Plaster Mâché” with cloth and armature and made an abstract sculpture of a woman holding a round object. I coated the cured plaster figure with my organic sealer and then mounted the female sculpture to a brass lampshade and added found objects. The plaster woman should not crack because I wrapped the fabric tightly to the broken steel grate (found in our yard) and made rounded edges. On the lampshade I wrote with white Posca marker: “A part of me knows no pain. A joy in me knows no cause. This is my essence.” It is something I heard and modified from a former yoga teacher. I used a Posca marker on the brass lampshade because painting on natural white pigment would not have been archival.

Roman Cement

With my success using plaster and RapidSet cement, I built my confidence and courage to make Roman cement. Many Roman bridges, aqueducts, and buildings remain intact without environmentally hazardous chemicals. At a thrift store, I found two colanders (for rinsing pasta) that I wanted to coat with this natural cement to make two huge bird eyes. I used the ingredients from a YouTube formula I found from Corporal Kelly (Corporals Corner, @recall5811), entitled “How to Make Roman Cement.” His ingredients for making a natural cement block called for aggregate (such as gravel); one could use hemp as an aggregate. However, since I intended to use the cement as a mortar over armature, I did not add gravel. Corporal Kelly patted the cement into a ball, and it did not stick to his hands. However, since I thought I needed to use fabric as a type of rebar, I added more water to the mixture. Watering down the cement ruined the recipe and caused it not to cure. I had to scrape it off everything and dry out the armature the next day. If I make Roman cement again, I will refrain from using fabric or add extra water to this mixture:

Roman Cement Ingredients
1 part hydrated lime for masonry – Type S (calcium hydroxide); slacked lime putty stucco is better.
2 parts volcanic ash (pozzolana)
Water (use sparingly). Do not use fabric; it will weaken the mixture.

Directions
Wear plastic gloves and a face mask. Mix the dry ingredients. Add water. Once the three ingredients are mixed well, the cement should not stick to one’s gloves, and it will form a playdough-like ball. Slacked lime putto stucco is better for the first ingredient because the limestone has already been heated and then soaked in water for several months. This strengthens the Roman cement.

Scoby Art and Sealer Experiments

I experienced difficulties in my material research, but only joy with scoby art and a sealer I created. I might be the first who has created fine art with kombucha scoby. Kombucha is a caramel colored non-alcoholic fermented drink, which is high in probiotics. Symbiotic Culture of Bacteria and Yeast (SCOBY) ferments sweet tea into kombucha and is a living culture consisting of many beneficial bacteria. Scoby is a beige, pancake-like rubbery biofilm of about .5” (1.27 cm). This mother or culture floats at the top of the sweet tea in a glass container as it is fermenting. The fermentation process takes about a week and one saves and strains the scoby at room temperature for the next batch and stores the strained kombucha in the refrigerator. I have been making kombucha with black caffeinated tea, white table sugar, and a scoby for over six years.On November 28, 2025, I saw nine petri dishes of dried scobies mounted on a board at the Zymoglyphic Museum in Portland, Oregon. Jim Stewart, co-owner of the private museum, glued the petri dishes to a light-up board and crudely covered the sealed petri dishes with black tape and paper on the front of his display. He said the scobies were not manipulated; instead, each kombucha scoby was placed into a sealed petri dish, dried in the sun, and displayed simply, with three petri dishes to a row and three rows total. His scientific display gave me an art idea. Needing to create art that would satisfy US and Canadian custom laws, I dried scoby with a different method than he and I manipulated mine. I also created abstract art and focused on the five art elements (color, line, shape, texture, form) as well as composition and my personal narrative (concept).

I used non-acidic glue to mount the dried forms I cut to create two wall-mounted works (Lunar Interventions and Moonlight Stroll, Figures 5 and 6). Figure 5 is interactive and the viewer can turn on and off the display screen. For Figure 5, I drilled a hole in the plexiglass for the on/off button on the bottom right of the screen and covered the ruler on the light-up tracing board with an old leather car shammy; I used natural pigments to coat this hand-made mat. In Figure 6 I glued the scobies to cotton paper. For Figure 7 (Misunderstood) I hand-sewed the scobies and used no glue. The scobies are visible in the middle of van Gogh’s sunflower, which one may interpret alternatively as a snake eye or human embryo. For Figures 5, 6 and 7 I included the dark brown globs that appear when I am straining the kombucha batches I make.

As mentioned in this report and as visible in Figures 2 and 4, I created a sealer for plaster, paper, and fabric mâché. It is a variation of gesso, but it has copious ground eggshells because eggs symbolize birth and create an organic vibe; both were important to the show’s theme about my rebirth. My formula has no pigment, so it differs from other handmade gesso recipes. The wall-mounted sculpturein Figure 8, In Her Eyes, is a sample of what the sealer looks like on paper.

Implications

Applications of this material research relate to one’s efforts to persist, reframe material searches across industries, cross boundaries, and rhizome around obstacles. I have not seen anyone using fabric and cotton mops with cement for small sculptures, using lime stucco putty as a cement coating for indoor sculptures, or creating scoby art. The sealers I saw and read about as ways to hide imperfections in dried plaster and papier/fabric mâché were not ideal for the environment. For example, drywall mud as a plaster coating has several additives, such as plasticizers. Thus, I created an organic sealer to hide defects. My website is https://www.3dbykathy.com if one is interested in seeing the art I created from this material research, asking me questions, or collaborating. I welcome this interaction across disciplines.

Conclusions

In summary, I found ways to continue my eco-practice for my artist residency and solo show in Canada. In Seattle, I work with found objects from nature, but Canadian and US custom laws prohibited driftwood, branches, and other flora from entry. I spent over one thousand hours researching materials and processes online, using ChatGPT, YouTube, and Facebook. I had no luck with hempcrete, vegan leather, and Roman Cement, but I will keep trying. I did have success using damp cotton rags and mop heads with RapidSet Cement All, lime stucco putty on cement with tooth (or cement surfaces I roughed up before they dried), manipulating kombucha scobies, and inventing an organic sealer. I was joyful when working with scoby and natural sealer and smelling my organic formulas inventions; I am very sensory and sensitive and I heal from using all my senses.

In my material research, I studied chemistry and how to apply it to my practice. I have no formal chemistry training, not even from high school, so this material research opened my mind regarding organic (plant-based) and inorganic (mineral-based) chemistry. For instance, I know now that I cannot use some organic ingredients (such the eggshell sealer I created) over the inorganic lime stucco putty because adding that organic material can cause a sculpture to peel or discolor. I also learned about materials around my home that constitute chemicals and ingredients needed in a formula. For instance, skim milk with water is casein or phosphoprotein, and one can save money by making one’s own casein versus buying it from a vender. I also became more flexible in my thinking and began to reframe my search for chemicals and products. I could not find a way to obtain calcium carbonate, but I learned that the free-range chicken eggs I was composting do contain substantial amounts of calcium carbonate. (Duck eggs have even more, according to one peer-reviewed experimental study I read.) I began to look across disciplines to find products. For instance, I could not get volcanic ash anywhere locally, so I found it in the form of chicken dust bath online. Thus, I went from the mineral industry (volcanic ash) to agriculture (hen and rooster dust baths). Instead of giving up on ingredients I needed if I could not find the material after an exhaustive search, I reframed searches for inexpensive, readily available products.

Bibliography

Cabra, David, “Pine Sawdust, Sodium Alginate.” Future Materials Bank (No date). Accessed March 23, 2026. Pine sawdust, Sodium alginate by David Cabra – Future Materials Bank

Camacho, Francisco A.J. “Climate-friendly Concrete Paves Path to Green Construction.” Scientific American (July 23, 2024): Accessed March 23, 2026. https://www.scientificamerican.com/article/climate-friendly-concrete-paves-path-to-green-construction/

Diaz-Basteris, José, Sacramento Rivero, Julio C., and Menéndez, Beatriz. “Life Cycle Assessment of Restoration Mortars and Binders.” Construction and Building Materials 326, 126863 (2022): 1-10, https://doi.org/10.1016/j.conbuildmat.2022.126863

Jalal, Parah, Srivastava, Vikas, and Tiwari, A.K. “Portland Cement at the Crossroads: Environmental Imperatives and Pathways to Sustainable Production.” IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) 22, 4 (2025). 1-10. DOI: 10.9790/1684-2204010110