76/24 Blend Architecture: The Three Numbers Behind OHZEHN-TEX, Disambiguated
76, 62, and 99.5 all describe this fabric. They measure three different things at three different levels. If you are the person who has to defend the claim to a compliance team, this is the page.
The OHZEHN-TEX 76/24 blend architecture is 76% bio-based polyamide (PA6.10, built from castor-oil sebacic acid plus petroleum HMDA, so the polymer itself is approximately 62% bio-based by mass) knit with 24% plant-derived stretch chemistry from a corn feedstock. Up to 0.5% traditional nylon is retained at the fiber-blend level in specific constructions for compression-grade rebound. Total platform: 99.5% plant-derived by fiber count.
1. The three numbers, disambiguated
Most of the confusion around OHZEHN-TEX comes from three percentages that get quoted in the same sentence and measure completely different things. Here they are side by side.
| Number | What it measures | At what level | Why it is not the other numbers |
|---|---|---|---|
| 76 / 24 | The blend ratio between the polyamide yarn and the stretch yarn | Fiber blend, in the knit | It says nothing about feedstock. It says how much of the fabric is structure and how much is stretch. |
| approximately 62% | Bio-based carbon content inside the PA6.10 polymer itself | Polymer chemistry, inside the 76 | PA6.10 is built from two monomers. One is plant-derived, one is not yet. This is the honest cap on that yarn. |
| 99.5% | Plant-derived content by fiber count at the finished-fabric level | Finished fabric | Excludes the up-to-0.5% traditional nylon retained in specific constructions. Counts fibers, not carbon atoms. |
The short version: 76/24 is a ratio, 62% is a chemistry ceiling, 99.5% is a fiber census. A product spec sheet that quotes 76% is describing the polyamide share of the blend. A marketing line that says 99.5% plant-derived is describing fiber count. Both are true. They are not the same measurement, and a materials team reading them as the same measurement will rightly ask questions.
2. Why 76/24 specifically
The ratio is a performance setting, not a branding decision. It is what the compression envelope demanded once elastane came out of the spec.
The 76% polyamide share does the structural work. It carries the hand, the abrasion resistance, the dye affinity, and the dimensional stability of the fabric. Push that share higher and you get a firmer, more stable fabric with less give, which is fine for a woven or a light base layer and wrong for a legging.
The 24% stretch share does the elongation and the recovery. It is what lets the fabric return to shape after being pulled to the limit of a deep squat, and what keeps a waistband from seating out after twenty wears. Push that share higher and you buy elongation at the cost of recovery consistency and dye-lot stability, because the two yarns take color differently and the wider the stretch share, the more that difference shows across a run.
Twenty-four percent is where those two failure modes stop overlapping. Below it, compression-grade rebound gets unreliable. Above it, color consistency across a 5,000 yard dye lot degrades and hand goes rubbery. The number is set by the bench, and it is validated per construction rather than assumed.
3. Why not 100% plant-derived
Because the chemistry is not there yet, and pretending otherwise is how ingredient brands lose credibility with the exact audience they need.
PA6.10 is a polyamide made by reacting two monomers. Sebacic acid, which comes from castor oil, is the plant-derived half. Hexamethylenediamine (HMDA) is the other half, and at commercial scale HMDA is still petroleum-derived. That split is why bio-based carbon in PA6.10 lands at approximately 62% by mass, per published PA6.10 chemistry. It is not a supplier choice. It is arithmetic on the monomer feed.
Bio-based HMDA exists in the literature and in pilot production. It is not yet available at the volume, price, and consistency that a production textile program requires. When it ships at commercial scale, the same PA6.10 polymer pushes past 95% bio-based carbon with no change to the fabric a brand is already selling. That is the single biggest upgrade sitting in front of this platform, and it arrives as a chemistry substitution rather than a reformulation.
The second reason is the 0.5%. Covered below.
4. What sits in the 24%
A plant-derived stretch polymer from a corn feedstock. Plant sugars are fermented into a monomer, which is polymerized into a stretch yarn.
What it is not: elastane. Elastane and spandex are the same fiber under two names, and chemically that fiber is segmented polyurethane, a petroleum-derived plastic. A 5% elastane blend is 5% plastic by weight and fails a plastic-free spec on a lot test. That is the entire reason the 24% exists in this form. The full route comparison, including mechanical stretch as an alternative, is on the plastic-free stretch fabric page.
The honest caveat: bio-based feedstock and biodegradability are separate claims. A corn-derived polymer is plant-derived. That does not make it biodegradable at end of life, and we do not claim 100% biodegradable on any OHZEHN-TEX construction. End-of-life profiles depend on the polymer family, and third-party data should be requested per lot, per construction.
5. What sits in the 0.5%
Conventional nylon. Up to half a percent, in specific constructions, at structural yarn junctions and in certain warp-knit finishes.
It is rebound insurance. In compression-grade categories the recovery curve runs at the edge of the envelope, and that residual conventional nylon is what holds the junction geometry through hundreds of stretch cycles. Constructions that do not need it do not carry it. Where it is present, it is on the spec sheet, per construction, per lot.
We publish it because a category-defining ingredient brand earns credibility by disclosing residuals rather than rounding them away. It is also why the platform-level claim is 99.5% plant-derived by fiber count and not 100%.
6. How the ratio flexes by category
76/24 is the platform baseline, not a single fixed recipe. The GSM band runs from 150 to 320 GSM, and the effective stretch share is tuned inside that band per category.
| Category | Typical GSM zone | How the architecture is tuned |
|---|---|---|
| Intimates | Lower band | Lighter constructions, stretch tuned for waistband and leg-opening recovery rather than whole-panel compression. Hand is the deciding variable. |
| Compression activewear | Upper band | Heavier knit, stretch share at the baseline, recovery validated over extended wash cycles. This is where the 0.5% retention typically appears. |
| Swim | Mid to upper band | Recovery under chlorine and salt is the design gate. Colorfastness testing runs alongside elongation testing rather than after it. |
| Base layers and tees | Lower band | Structure share carries more of the job. Some constructions need far less stretch share than the baseline. |
Which zone your program lands in is settled during the chemistry-match step of the buying process, before you spend anything on samples.
7. Frequently asked questions
Why is OHZEHN-TEX not 100% plant-derived?
Two reasons, at two different levels. At the polymer level, PA6.10 is made from sebacic acid (castor-derived) and hexamethylenediamine (still petroleum-derived at commercial scale), which caps bio-based carbon at approximately 62% by mass per published PA6.10 chemistry. At the fiber level, specific constructions retain up to 0.5% traditional nylon for compression-grade rebound, which is why we publish 99.5% plant-derived by fiber count rather than 100%. When bio-based HMDA reaches commercial scale, the polymer figure moves past 95%.
Does the 24% stretch component contain plastic?
It is not elastane. Elastane and spandex are segmented polyurethane made from petroleum. The 24% in the OHZEHN-TEX architecture is a plant-derived stretch polymer built on a corn-derived feedstock, which is why the fabric clears a plastic-free spec that any elastane blend fails. It is still a polymer, and bio-based feedstock does not by itself make a polymer biodegradable. We do not make a 100% biodegradable claim on any construction.
What is in the 0.5% traditional nylon?
Conventional PA6 or PA6.6 nylon, used at up to 0.5% in specific constructions at structural yarn junctions and in certain warp-knit finishes. It is rebound insurance for compression-grade categories where the recovery curve sits at the edge of the envelope. It is disclosed on the spec sheet per construction. Constructions that do not need it do not carry it.
How does 76/24 compare to Fulgar EVO's ratio?
They are not the same kind of number and should not be compared directly. Fulgar EVO is a PA11 yarn made from castor oil, so its bio-based figure describes a single yarn's polymer content. 76/24 describes a two-component fiber blend at the fabric level: 76% bio-based polyamide yarn plus 24% plant-derived stretch yarn. The comparable numbers are polymer-level bio-based carbon, where PA11 is fully castor-derived and PA6.10 sits at approximately 62% because of the petroleum HMDA monomer. The trade is that a PA11 yarn on its own does not carry the stretch component a compression garment needs. Fuller comparison on the OHZEHN-TEX vs Kintra page.