Recycled polyester has moved from a premium talking point to a line item. That is mostly good, and it has produced a specific kind of mess: suppliers who genuinely run certified rPET, suppliers who blend a little recycled content and describe the whole product as recycled, and suppliers who use the word because a competitor did. The material is real. The claim is what needs verifying.
What rPET actually is
Recycled polyethylene terephthalate for textile use comes from three main streams, and they are not equivalent:
- Post-consumer bottle flake — the dominant source. Bottles are collected, washed, flaked and re-melted into filament. Well established, widely certified, and the stream most netting suppliers actually use.
- Post-industrial waste — factory offcuts, waste filament, rejected yarn. Cleaner and more consistent than bottle flake, but the volume is limited by how much waste the industry generates.
- Fibre-to-fibre recycling — textile back into textile. Technically the most attractive story and the smallest volume, because sorting blended fabrics at scale remains hard.
“Ocean-bound plastic” is a sourcing narrative layered on top of the first category: material collected from coastal areas at risk of entering the ocean. It is a real programme with real audit rules, and it is also frequently used to imply a higher recycled percentage than the product contains. Ask for the number, not the story.
GRS versus RCS
Two standards from the same body, Textile Exchange, cover recycled content claims. They are routinely confused, and the confusion usually runs in the supplier's favour.
| Requirement | GRS (Global Recycled Standard) | RCS (Recycled Claim Standard) |
|---|---|---|
| Recycled content threshold | 20% minimum for certification | 5% minimum |
| Chain of custody | Required at every stage | Required at every stage |
| Social criteria | Yes — labour, wages, hours, health and safety | No |
| Environmental criteria | Yes — energy, water, wastewater, emissions | No |
| Chemical criteria | Yes — restricted substances, ZDHC MRSL alignment | No |
| Typical buyer | Brands making public sustainability claims | Buyers who only need content verification |
The practical difference: RCS proves the recycled content and nothing else. A product can be RCS certified while being made in a factory with no wastewater treatment and no labour policy. GRS covers all of it. If your customer is a European retailer with a published sustainability report, RCS will not survive their supplier questionnaire. If you are buying for your own label and only need the content figure to be true, RCS is cheaper and sufficient.
Both standards require certification at every stage of the chain — recycler, spinner, knitter, dyer, and the final trading company. That is the part that trips up traders: a netting factory with GRS certification cannot issue a GRS claim on cloth made from uncertified yarn. The chain has to be unbroken from the bottle to the box.
The two certificates that matter
Almost every problem in this category comes from accepting one document when two are needed.
Scope Certificate (SC) — issued to a specific facility, valid for one year, listing the product categories and processes that facility is certified for. It proves the factory can produce certified goods. It says nothing about any particular order. An SC is the document suppliers send most readily, because it is easy to send and does not commit them to anything.
Transaction Certificate (TC) — issued per shipment, naming the buyer, the quantity, the product and the recycled content percentage, and referencing the SCs of every upstream supplier in that chain. This is the document that proves your goods are certified. It is issued after the transaction and it is the one that matters at customs, at audit, and at the point where a brand asks for evidence.
If a supplier can produce an SC but goes quiet when you ask for a TC, that is the answer to your question. The material may well be recycled; it is not certified for your order.
The physical trade-offs, honestly
Recycled polyester is not identical to virgin polyester, and a supplier who claims otherwise is either misinformed or managing you. The differences are real but usually manageable:
- Molecular weight distribution is wider. Every melt cycle shortens some chains. Unless the recycler runs solid-state polycondensation to rebuild viscosity, the intrinsic viscosity of rPET sits slightly below virgin resin. Lower viscosity means slightly lower tenacity in the drawn filament.
- Colour varies between batches. Bottle flake arrives in mixed colours. Most rPET filament is either dope-dyed to a fixed shade or solution-dyed to mask variation. White netting is the hardest shade to hold consistent, which is unfortunate given how much netting is sold in white.
- Strength is typically a few percent lower. In finished netting the difference is usually inside the tolerance band of the specification, provided the yarn was made to a controlled IV. It becomes visible when a supplier substitutes rPET into a construction designed for virgin yarn without re-engineering the denier.
- Spinning waste is higher. Break rates on recycled filament run above virgin, which is part of why certified rPET costs more rather than less.
The engineering response is straightforward: specify the bursting strength you need, not the resin you assume will deliver it. A 100D rPET at 40 GSM will comfortably exceed the 405 kPa reference figure if it was spun properly. A 75D rPET pushed into a 30 GSM construction designed around virgin yarn may not.
Red flags on a quotation
- “Recycled material” with no percentage. Recycled content is a number. A claim without a number is a mood.
- A GRS logo on a document that is not an SC or TC. Logo use requires approval from the certification body. A logo pasted into a brochure proves nothing.
- Certification offered “on request after order.” TCs are issued against shipped goods, but the certified chain must exist before production starts. If it cannot be demonstrated pre-order, it does not exist.
- Certification held by a different legal entity than the one invoicing. Common in trading arrangements. It can be legitimate, but you need the TC to name the entity that actually shipped, not a sister company.
- A recycled percentage that changes when you ask twice. Recycled content is fixed by the yarn lot. If the number moves, nobody is measuring it.
What to ask for, in order
- The Scope Certificate, with the expiry date and the product categories visible.
- The recycled content percentage, by weight, for the specific fabric you are buying.
- Which standard applies — GRS or RCS — and confirmation of which criteria are therefore covered.
- Confirmation that a Transaction Certificate will be issued against your shipment, and in whose name.
- The bursting strength test report for the recycled construction, not the virgin one. This is the check that catches substitution.
Five questions, one email. A supplier running a genuine certified chain answers all five in a day. A supplier running a marketing claim answers two and changes the subject on the third.
What this means when you buy
Recycled content is a documentation purchase as much as a material purchase. Treat it that way:
- Budget for the certificate, not just the cloth. Certified rPET carries a real premium because spinning yields are lower and the audit chain costs money. A quote that matches virgin pricing exactly is worth a second look at the paperwork.
- Separate the claim from the performance spec. Recycled content tells you nothing about bursting strength, aperture or UV life. Keep the two conversations apart, or the sustainability story will quietly absorb the engineering questions.
- Get the TC before the balance payment. Once the balance clears, your leverage on documentation drops to near zero. Build the TC into the payment terms.
- Match the standard to the market. EU retail and brand supply chains generally need GRS. Distributor labels and private-label programmes often accept RCS. Choosing GRS when RCS would do adds cost for criteria your customer never asked about.