Why the model decides the claim
A chain of custody is not a document. It is a model: a rule for how a claim is allowed to travel alongside material as it changes hands. Two parties can hold the same certificate reference and make entirely different assertions, because they work under different models. Reading a custody claim without knowing the model is reading half a sentence.
There are two models in common use in textiles, and they sit at opposite ends of a trade between cost and strength.
| Model | What is physically true | What the claim asserts | What an auditor can check | Where it fails for post consumer stock |
|---|---|---|---|---|
| Segregation | Certified material is kept apart from other material through every step. | This item is made of the certified material. | Physical separation, batch records, reconciliation of input to output. | There is no certified input batch to segregate. The bale is a mix by definition. |
| Mass balance | Certified and uncertified material are processed together. | A stated share of output corresponds to certified input over a period. | The ledger: input volumes, allocation rules, output volumes. | There is no upstream producer to declare the input volumes the ledger depends on. |
Where legacy flows break both models
Both models share an unstated assumption: that somewhere upstream there is a producer who knows what the material is, can certify it, and has a commercial reason to. Every certificate in a textile supply chain runs forward from that party.
A post consumer bale has no such party. The material arrives from collection containers, charity routes and municipal schemes, mixed from thousands of unrelated households. The batch is an accident of collection geography, not a production run. German collectors handle around 1.3 million tonnes a year and sort into as many as 350 fractions; not one of those fractions has a producer who will issue a certificate for it, because the producers who made the garments have not been in the chain for a decade.
This is why so much recycled content in textiles is post industrial rather than post consumer, and why less than 1% of textiles are recycled fiber to fiber. It is not only a technology limit. It is a custody limit: the material that most needs to be recovered is the material with no paperwork behind it, and the systems for making claims were built for the other kind.
Event based custody
The replacement for a certificate that runs forward is a trail that is recorded as it happens. GS1 EPCIS 2.0 is the standard for that: it models what happened, when, where and why, in a form other systems can query rather than read.
Its four event types describe a sorting facility precisely, which is the useful part.
- An object event: a bale arrives at the facility and is observed at a reception point.
- An aggregation event: items are disaggregated out of that bale, or aggregated into an output fraction.
- A transaction event: a fraction is transferred to a recycler under a specific business transaction.
- A transformation event: the recycler consumes the fraction and produces fibre, which is the point where identity as a garment ends and identity as a material begins.
Recorded this way, custody is a queryable history rather than a folder of documents assembled after the fact. The question "where did this fraction come from" stops being a research task.
Fact level provenance
Event data says where material went. It does not say why anyone believes what the material is. That is a second and separate trail, and PROV-O is the model for it: every asserted fact carries a link to the source it was derived from and the activity that derived it.
The difference is easiest to see in one sentence. "The record says 62% cotton" is a value. "The record says 62% cotton because this care label said so, read at this station, at this time, and scored this confidently, with two other sources agreeing" is evidence. Under audit, only the second one survives a follow up question.
What an item record adds at the line
If there is no producer upstream to originate the data, it must be originated where the material physically is. That means at the sorting line, per item, at line speed: identity, composition, origin, brand and care, each read from the documentation the garment already carries, each with a calibrated confidence and a link back to the document it came from.
The scale that makes this a custody instrument rather than a sampling exercise is the throughput: 23,800 items an hour across 16 concurrent capture streams, with routing decisions inside a 50 ms ceiling. Roughly a quarter of items clear a 0.9 confidence gate and route on their own; the rest go to assisted review, where a person decides with the label crop in front of them. Every item ends with a record either way, and the record is what the custody events then attach to.
This is the substitution that matters. Where a certificate would have travelled forward from a producer, a record is created at the point of handling and travels forward from there. It does not pretend to know what happened before the bale arrived. It does establish, from that moment on, an unbroken chain of evidence anchored in documents that physically exist.
One record, two obligations
The same record discharges two duties that are usually handled by separate systems. For a brand buying recycled input, it is the audit evidence behind a recycled content claim, which under EmpCo, Directive (EU) 2024/825, has had to be substantiated since 27 September 2026.
For a producer responsibility scheme or a public waste authority, the same records aggregate into mass flow evidence: in Germany, the Mengenstromnachweis. Under Directive (EU) 2025/1892 the fees producers pay are eco modulated, which only functions if what was collected and where it went can be established. Aggregating item records gives that answer at product resolution rather than at truck resolution.
Two obligations, two audiences, one underlying set of facts. That is the argument for recording custody at the item rather than the bale: the bale level answer has to be reconstructed for every question, and the item level answer only has to be produced once.