More and more European brands add one line to the enquiry: can this woven label be made from recycled polyester? The question looks simple; in delivery it comes down to three things — what recycled content, where performance differs, and what proves it is actually recycled. The third is where projects fail: recycled yarn without a transaction certificate does not exist as far as a brand audit is concerned.

This guide covers four things: what rPET actually is, which trims genuinely suit it, how the GRS and transaction certificate chain works, and the five points to check when buying. There is also one red line on green claims — you only need to cross it once.

1. What rPET Is and How It Differs from Virgin Polyester

rPET is polyester spun again from recovered PET, mostly beverage bottles, after washing, flaking, pelletising or depolymerisation. Two routes exist: mechanical recycling melts and re-pelletises at low cost, but polymer chains are shortened and colour options narrow; chemical recycling depolymerises PET back to monomers and re-polymerises it, close to virgin quality, with cost and capacity as the barriers. Content is commonly 30, 50 or 100 percent, and the actual figure must appear on both label and BOM.

  • Colour: mechanically recycled lots drift more in hue than virgin resin; pale and bleached shades are hardest, dark and black are actually the steadiest
  • Strength: lower molecular weight costs roughly 5–15 % tensile strength; fine sewing thread shows it first, coarse webbing hardly notices
  • Source: bottle flake, polyester waste yarn and post-consumer garments each sit in different collection systems and certification paths; bottle-to-fabric does not mean better quality, only a different feedstock

2. Which Trims Genuinely Suit rPET

Trim Fit What to watch
Woven label yarn Very good Narrower colour gamut, pale and high-whiteness shades are hard; raise yarn twist to keep warp breakage down
Sewing thread Partly Trial a small batch at high speed and on heavy fabric to watch thread breakage; be cautious below 40s fine counts
Webbing and binding tape Very good Slightly stiffer hand, hot-cut edges behave close to virgin; confirm shade deviation on pale colours
Poly bags Very good Slightly lower clarity and higher haze, so check a real sample for display packs; reseat the sealing temperature
Tag string and cotton cord Not applicable The material is not polyester and sits in another recycling system; for cotton cord look at recycled or organic cotton routes

3. The Traceability Chain: GRS and Transaction Certificates

GRS, the Global Recycled Standard, is the certificate most often named for garment trims, and it governs two things: recycled content and the chain of custody. In practice that means a transaction certificate, issued by the certified party against the quantity actually shipped, stating product, recycled content, buyer and seller, and the matching invoice — and the quantity can never exceed the certified input it bought. One uncertified link and the batch stops there.

  • A TC is issued per order or lot: it is not a standing certificate — each shipment has its own, with a unique number and quantity
  • State the content exactly: if the BOM says 50 %, the TC must say 50 %; a vague about half gets sent straight back by an auditor
  • Logo use needs approval: you cannot print the GRS mark on a hang tag or packaging on your own; the certification body must approve it, and misplacing it carries both infringement and false-claim risk
  • Clients may want more than GRS: RCS has a lower bar, ISCC PLUS works on mass balance, bluesign focuses on chemical management — ask which scheme the client accepts before quoting

4. Five Checks When Buying

  1. Scope: does the certificate's product category actually cover woven label yarn or sewing thread? Many only cover fabric
  2. TC against the order: do quantity, content and lot number line up one to one with this shipment?
  3. Lot colour: recycled lots vary more, so if one shade runs across two batches, keep a signed sample from each
  4. Physical data: compare tensile, abrasion and ironing temperature against the virgin version in a side-by-side test, not a verbal assurance
  5. Quotation basis: price follows content and yarn count — 30 % and 100 % are not the same money; comparing unit prices alone distorts the decision

5. Do Not Turn a Material Story into an Illegal Claim

Green claims face tighter scrutiny in the EU: bare adjectives such as eco-friendly, sustainable or green without specific evidence are high-risk wording. What works is specific, verifiable and bounded — a hang tag reading woven label in 100 percent recycled polyester, GRS certified, transaction certificate number available on request, is far stronger than a green leaf icon and survives a follow-up question.

💡 Tip: if a supplier cannot produce a transaction certificate and offers only a self-declaration, treat the yarn as ordinary polyester and put zero recycled content in the BOM. Adjusting later when the certificate arrives is far easier than explaining at a brand audit.

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Planning recycled polyester woven labels, thread or bags? Send the target content, certification requirement and expected volume; we confirm yarn supply and whether TCs can be issued per lot before quoting. Sampling 3–7 days, bulk 10–25 days.

Ask about rPET trims →