Hemp's Performance Future Starts with Yarn
As a materials and apparel specialist, my work is often getting natural fibers adopted for what they do, not just for their sustainability story. I want brands to choose natural fibers as performance fibers, and I believe nature does have the answers.
Hemp has become my new favorite fiber. I own pieces from both Opera Campi and Jungmaven, and I wear them constantly. Lately I've been deep diving into the fiber, its problems, and how better yarns and processing could solve them.
This piece is about knitted hemp. Woven hemp is its own story, and a more mature one. Knits need fine, even, flexible yarn, and that's exactly what hemp struggles to become.
My argument is this. Hemp's biggest barrier isn't the fiber. It's waste: fiber lost in processing, and fabric lost to defects at the knitting machine. Most of that waste is created upstream, at retting, degumming and spinning. Solve hemp at the spinning stage and you cut the waste, bring down the cost, and make lighter hemp knits possible. That's how hemp gets into more brands and more performance product.
Last year I covered hemp's modern supply chain: farming, retting and certifications. This piece goes further down the chain, into the yarn.
Why aren't more brands using hemp?
More brands aren't using hemp because it wastes too much at every stage, and that waste shows up in the price. The numbers are stark.
At the fiber stage: Opera Campi says 80% of the plant is lost getting to usable fiber, according to Il Sole 24 Ore.
At the knitting machine: Jungmaven loses 10–15% of its hemp fabric to defects. Conventional yarn runs closer to 2%, according to Lampoon's interview with founder Robert Jungmann.
Jungmann explains the defect problem simply. Run a finger down cotton yarn and you never feel a bump. Run a finger down hemp yarn and you might feel one every now and then. On a knitting machine, that bump is trouble:
An oversized slub can snap a needle, which is slow and expensive to fix.
The same slub can tear a hole in the fabric.
Every rejected section gets priced into the product. Jungmann says that cost reaches the customer.
For a brand deciding whether to add hemp to a line, that's the whole story. Hemp costs more, the fabric is less predictable, and finding a supplier who can deliver consistent quality is hard. The fiber isn't the problem. The yield is.
Two tees, two strategies
The two hemp tees in my closet show the two ways to deal with defects. Jungmaven made the fabric heavier. Opera Campi went upstream to the fiber and the yarn, and ended up with a much thinner shirt.
Jungmaven: the Jung Tee
55% hemp / 45% organic cotton jersey
Weight: 5 oz jersey (about 170 g/m²); the Baja tee is 7 oz
Strategy: moved to a heavier fabric with fewer manufacturing errors
Yarn: blended yarn spun in China; cut and sewn in LA
Price: about $100 at launch, now about $80
Stated challenges: 10–15% rejects, with the cost passed to the customer
Opera Campi: the Burro Canapa tee
100% hemp
Weight: the whole shirt weighs 98 g
Strategy: sourced premium long fiber, wet-spun it, and knits slowly
Fiber: the "Dragon" cultivar from northeast China, chosen after a long search
Price: €110
Stated challenges: 80% fiber loss, needle breakage, creasing, dye cost and color consistency
Sources: Lampoon on Jungmaven, Il Sole 24 Ore, Opera Campi Origin, Giardini di Toscana – Burro Canapa tee, Drop – Jungmaven Baja 7 oz tee.
The weights aren't measured the same way, since one is a fabric weight and one is a whole garment. Still, a 5 oz jersey tee will weigh noticeably more than 98 grams. Opera Campi's shirt is the lighter one by a wide margin.
Heavier fabric was a smart fix for Jungmaven. Thicker yarn is more forgiving on the machine. But it's a workaround: it uses more fiber per shirt to hide a yarn problem. Opera Campi's thin tee proves the other path works. When the fiber and the yarn are right, hemp can be light. The catch is that Opera Campi pays for it in fiber loss, slow knitting and price.
Back to the source: where defects are born
Most hemp knit defects are found at the knitting machine but born much earlier. To reduce them, you have to go all the way back to retting, degumming and spinning, and work there with the spinner.
Hemp doesn't arrive as individual fibers. It arrives as bundles of fiber cells glued together with pectin, lignin and hemicellulose. How cleanly those bundles are opened decides how fine and even the yarn can be. Compared with cotton, hemp is also stiffer, coarser and much more variable in fineness. NC State's Wilson College of Textiles notes that leftover hurd causes processing problems, and that poorly decorticated fiber doesn't separate during carding and drawing. That's the bump in the yarn.
Growing and harvest: the wrong cultivar or harvest timing gives uneven fineness and strength, which shows up as thick and thin places across a whole lot.
Retting: weather-dependent dew retting leaves fiber under- or over-retted, so quality and color swing from lot to lot.
Decortication: woody hurd and shive left in the fiber become specks, slubs and broken needles.
Degumming: gums left behind, or fiber damaged by harsh chemistry, make fibers that won't separate and yarn that's weak and hairy.
Spinning: uneven drafting, no slub clearing and mixed lots cause slubs, holes, thin spots and barré.
Knitting: cotton machine settings used for hemp lead to needle breaks and dropped stitches.
Inspection: with no agreed line between a natural slub and a fault, good fabric gets thrown out.
Follow that chain and the point is clear. By the time fabric reaches inspection, most of the waste is already locked in. Fix the fiber and the spinning, and the knitting and inspection problems shrink with them.
The two routes to hemp yarn
Hemp has two main routes to yarn, and the two tees above sit on opposite sides. Each route moves the difficulty to a different stage.
Wet-spun long line (the Opera Campi route)
Long hackled hemp, processed like flax
The roving passes through hot water to soften the gums, then is drafted fine
Makes a finer, smoother, less hairy yarn
In knits: a light, beautiful hand, but the stiff yarn breaks needles, so you knit slowly
Where the waste sits: fiber loss in hackling, and slow, costly knitting
Cottonized short staple (most hemp/cotton jersey)
Hemp cut and degummed to a cotton-like staple
Spun on the cotton system: ring, compact, open-end or vortex
Makes a coarser, hairier yarn, especially open-end
In knits: runs on standard machines, but evenness falls as the hemp percentage rises
Where the waste sits: defects from incomplete degumming and uneven yarn
The fine-yarn gap is real. European wet spinners mostly make weaving yarns, and the US has had no commercial hemp spinning. Fine hemp knitting yarn still comes mostly from China.
Hemp vs linen: why choose hemp?
If linen already has a mature, fine-yarn supply chain, why push hemp? The answer is where and how it grows, not fiber strength.
Hemp grows almost anywhere, including the US. Flax for linen grows almost entirely on a coastal strip from the Netherlands to Normandy.
Hemp is easy in the field. It outcompetes weeds with little herbicide and is a strong rotation crop.
The whole plant has value. The hurd goes to construction materials and animal bedding, so that 80% loss isn't all waste.
It's not stronger than linen. One lab study found hemp about 20% lower in tensile strength than flax after processing. That's a claim worth retiring.
Linen wins on yarn today because Europe invested in its processing for generations. Hemp hasn't had that investment yet, which is exactly why the spinning stage is where the work belongs.
Sources: Fashion Network – flax sector study, Università Cattolica – flax vs hemp fibre yield and mechanics, Fibre2Fashion – hemp vs linen, NC State.
Where better hemp yarn takes us: 100% hemp and new blends
A lighter, cleaner yarn opens two paths, and I'm excited about both. The first is better 100% hemp knits. The second is a whole range of blends that hemp can't get into today.
100% hemp
I love a 100% hemp tee. Opera Campi's 98 g shirt proves hemp can stand on its own in a light knit.
Hemp brings strength, abrasion resistance and a dry, cool hand, and it softens with every wash.
It's a single-fiber garment, so it biodegrades without shedding microplastics and has no blend to separate at end of life.
Finer, more even yarn would make light 100% hemp knits less wasteful to produce and more affordable, not just a luxury product.
Blends to explore
Hemp/merino
Hemp adds durability, abrasion resistance and a drier hand
It could replace the nylon many merino knits use for durability, keeping the garment all-natural
Finer yarn unlocks lighter merino-led tees, base layers and midlayer jerseys
Hemp/organic cotton
Hemp adds strength and longevity, and replaces part of the cotton
Finer yarn unlocks lighter everyday and performance tees, not just heavy ones
Hemp/lyocell
Hemp adds strength and structure; lyocell adds softness and drape
It's an all-cellulose alternative to fully synthetic travel and lifestyle knits
Finer yarn unlocks fine jersey for travel and lifestyle-performance product
Of the blends, hemp/merino is the one I'm most excited to test. Replacing a nylon durability component with hemp would be a meaningful step, if the abrasion results hold up. A few rules for making it work:
Match staple lengths to the spinning system. Long-line hemp suits worsted or semi-worsted spinning with longer merino. Cottonized hemp suits short-staple spinning with shorter wool.
Decide which fiber is in charge. Opera Campi's Lanapa is merino-led (66/34). Jungmaven's Baker tee is hemp-led (55/45).
Put merino at the skin. Hemp is coarser than fine merino, so keep it inside the yarn structure.
Solve dye before you sample. Hemp takes reactive or direct dyes; merino takes acid dyes. Dye before blending, cross-dye on purpose for a heather, or leave the hemp natural and dye only the merino.
Skip superwash if you want the biodegradable story to hold.
I cover this blend's fiber science in more depth in Six Natural Merino Blends.
What we should be doing: work upstream with the spinner
The place to be is at the spinner's table, not the knitter's. Brands that want better hemp have to stop buying stock fabric and start developing yarn with the people who make it, all the way back to the fiber.
Choose fiber for spinning. Ask for cultivar, harvest timing and retting method, and test fineness and length uniformity per lot.
Get retting under control. Controlled retting and enzyme methods give a more consistent starting fiber than weather-dependent dew retting.
Degum cleanly and completely. This is where cottonized hemp is won or lost. CRAiLAR proved enzymes could soften bast fiber without changing its chemistry. Renaissance Fiber in North Carolina now degums US hemp with a low-impact process and has supplied Patagonia since 2022.
Write the yarn spec together. Agree count, evenness limits and spinning system with the spinner. Ask for Uster reports on thin and thick places, neps and hairiness. Use compact spinning and electronic slub clearing, and keep one lot per run.
Set up knitting for hemp. Slower speeds, proper waxing, and needle and lint control.
Agree what a natural slub is. Write it down before production, so good fabric isn't thrown out.
Measure the waste. Track rejects by defect type before and after each change, so you know which fix worked.
The US is starting to build the upstream pieces. In October 2026, IND HEMP added a cottonizing line at its plant in Fort Benton, Montana, to ship ready-to-spin fiber. NC State is working with BioPhil Natural Fibers on hemp/cotton yarns from 10% to 40% hemp. The next step is fine hemp/merino and hemp/lyocell yarns built for performance knits.
One caveat on environmental cost: hemp is a low-input crop, but harsh chemical degumming can undo that. The low-impact story only holds if the fiber is processed cleanly.
Questions to ask your spinner and mill
What cultivar is this fiber, how was it retted, and how was it degummed?
How much shive is left, and what are the fineness and length uniformity per lot?
Which spinning route did you use: wet-spun long line or cottonized? Ring, compact, open-end or vortex?
What's the finest count you can spin consistently at this hemp percentage?
Can I see the Uster report for this lot? Is the yarn electronically cleared, and at what settings?
Will my run come from one spinner and one yarn lot?
What's your current reject rate on hemp knits, and how does it split by defect type?
How do you define a natural slub versus a defect at inspection?
For hemp/merino: what's each fiber's staple length, which sits at the surface, and how will both be dyed at production scale? Is the merino superwash?
Final thought
Hemp isn't held back by the plant. It's held back by waste, and most of that waste is made before the yarn ever reaches a knitting machine. Jungmaven's heavier tee and Opera Campi's 98 g tee are two answers to the same problem. The next answer is a fine, clean, consistent yarn that makes light hemp knits affordable. That's what gets hemp into more brands, more performance blends, and more of what we wear every day.
That's the work I want to do: going upstream with spinners, building better yarns, and testing them in real garments. If you're working on hemp fiber processing or spinning, I'd love to compare notes.
Bonie Shupe is the founder of Rewildist, a product design and development consultancy specializing in sustainable materials, circular product design, and sourcing strategy. She has 25 years of experience in sustainable and outdoor active apparel, including at Ibex, Paka and Spyder.