How I make a microbe shirt
Or: how I figured out these freaky little t's, even though I still don't really know what's going on.
This t-shirt was made in a compost pile.
If that seems too weird to be true, I am totally with you. When I first figured out how to do this, I also thought it was very weird and I was possibly crazy. Was somebody actually sneaking into my garden at night and swapping the regular t-shirts I had put in my compost pile with these little freaks? But after I did it a few more times, I realized no — no tricks! No magic, even. This was just some good, old-fashioned, albeit slightly unexpected science.
The patterning you see in the photo above was produced entirely by the naturally-occurring microbial action in a thermophilic compost pile, a celestial-seeming snapshot of what would otherwise be the entirely invisible action of decomposition. It’s one of the cheapest and most DIY ways I’ve ever found to “see” microbes at play, no expensive microscopes required. It is also, in my humble opinion, just a very cool looking shirt.
The process for making these originally came about a couple years ago, when the guys at Cactus Store in LA hit me up for an experiment: could I partially compost some t-shirts for them to sell? They weren’t sure how the cotton would hold up in the piles and neither was I, but I was game to give it a shot. The first few experiments failed horribly because I left the shirts in the pile for too long and they broke down into nothing. But I kept trying, iterating on every factor imaginable: type of fabric, length of time in the pile, ingredients for the pile, temperature range, and more.
Eventually, I pulled a shirt from the pile that looked… different than the others had. The fabric was still intact, but I noticed a white fungus had crusted along the left edge of the sleeve and hem. When I wiped it away, the distinct tie-dye-like patterning was left behind. It was so neat looking. When the finished items were eventually posted for purchase, they sold out in under an hour. Proceeds supported the food justice organization that owns the land where I community compost.
Since then, I’ve continued to make the occasional microbe shirt in my compost pile—although I’ve never documented how I do it anywhere before. Truthfully, that’s because I still don’t entirely know how it works. I’ve fine-tuned the process itself over the months using only my intuition and my sense of how my specific piles work, but I still have never formally IDed the white fungus. It could be a particularly thick burst of actinobacteria, which I’ve written about before. (They are famously responsible for the “earthy” smell of earth.) But I don’t know!
Maybe I don’t ever want to.
Part of the joy of the shirts is their essential mystery. I never know how they’re going to come out, or whether they will at all. Some shirts go into the pile, never to be seen again. Others come out glorious and strange and star-like. You just never get to know in advance! Compost is an unpredictable medium.
Every shirt takes about 3 or 4 days to make, but making the compost pile that houses them can take weeks. It has to be a very hot compost, and the shirts have to be added at a very specific moment in the process of the pile heating up. Typically, I try to put them in around 120°F and let them sit while the pile climbs up to around 165°F. They need to be added and pulled out at just the right moment, so the patterning looks distinct and clear, but the shirt has not disintegrated. I also always wet the shirts thoroughly before adding them, and I bunch them into a ball before burying them a foot or two down in the pile.
Over time, I have experimented with many brands of t-shirts, but by far the best blanks I’ve ever found for doing this with are the ones from Everybody.World. Their garments are sturdy, in addition to being made from plastic-free cotton scraps, with 100% cotton thread and low-impact dyes. I’ve also had my compost piles tested after using Everybody.World blanks to make these shirts, and have not seen any contamination or other issues. (In fact, a recent assessment of a post-shirt pile by my friend Lynn Fang revealed astonishing levels of fungal activity.)
I’ve never sold the finished products since working with the Cactus Store. When a t-shirt turns out particularly cool, though, I always send it to a friend. I’ve been keeping a mental list of people who have expressed interest at one point or another, and slowly making my way down it. Brands do hit me up wanting to produce them commercially, but I have to laugh at how non-viable this would be to do at scale. Another thing I love about it. They will always be essentially secret, protected from the slow and endless soul-drain of commodification. The pile will do what she wants, when she wants. On her own terms. Forever.
Love,
Cass
PS. If you’re reading this now and you want to experiment with making your own microbe t-shirt, I’d love to see the results. Let me know.
This is extremely cool! One more way to integrate yourself into your garden , or maybe your garden into yourself?
Art that may go viral…