Supplier questions
What to ask a supplier, test by test
Use these cards as a request list. A supplier that cannot answer a card should say so in writing; that is useful information too.
The seven cards
T-01Thickness
- Ask for
- Total thickness in mm as mean and range, the number of readings, and whether the coating layer is counted.
- Method seen
- No method number for total thickness was verified. ISO 17186 turns up in searches but measures the surface-coating layer only.
- Why it matters
- Sets weight, cutting and sewing behaviour, and whether two samples can be compared at all.
- Third-party data point
- Third-party listings give 0.57 mm for one cactus-based sheet and 1.43 mm for one pineapple-fibre sheet.
- Kora status
- Not published
T-02Tensile strength and elongation
- Ask for
- Strength at break (N/mm² or MPa) and elongation (%), in both length and width, on conditioned specimens.
- Method seen
- ISO 3376:2020 is the leather method named in listings. Confirm the edition with ISO or a test house.
- Why it matters
- Seams, straps and upholstery load the sheet in different directions.
- Third-party data point
- A third-party study put one alternative at 20.8 N/mm² against 39.5 for real leather. Academic papers on bacterial cellulose range from about 5 to 212 MPa, so a paper is not a datasheet.
- Kora status
- Not published
T-03Flex resistance
- Ask for
- Cycles to first visible damage, the damage grade after the cycles, tested dry and wet.
- Method seen
- ISO 32100 is the method one materials library used. Confirm the edition.
- Why it matters
- Bag corners, shoe uppers and wallet folds fail by flexing.
- Third-party data point
- Listings show 5,000 cycles to grade 2 or better for one material and 150,000 for another. The spread is the point: ask for the number.
- Kora status
- Not published
T-04Abrasion
- Ask for
- Cycles to wear-through or to a defined change, with the abradant, the load and the method.
- Method seen
- ISO 26082-1 (Martindale, for leather) appears in listings. ISO 5470 and ISO 12947 were not verified.
- Why it matters
- Edges, handles and seats are rubbed daily. Colour rub-off is a separate test.
- Kora status
- Not published
T-05Water absorption
- Ask for
- Mass gain in percent after a stated immersion time, and size change after wetting and drying.
- Method seen
- No method number was found in our sources.
- Why it matters
- Sheets made from cellulose may react to water differently from coated fabrics. This is our working assumption, not a measured finding.
- Kora status
- Not published
T-06Composition of layers
- Ask for
- Every layer named: base material, reinforcement, coating, dye, plasticizer, with approximate mass shares, and any synthetic polymer in the stack.
- Method seen
- No test method; a written declaration plus, ideally, a lab analysis.
- Why it matters
- Wording about origin or end of life applies to the finished product, not only to its base fibre. One Indonesian lab study of a nata de coco sheet used polyurethane as reinforcement and a synthetic plasticizer.
- Kora status
- Not published
T-07Production status
- Ask for
- Lab prototype, pilot or commercial run. Sheet size, lot-to-lot variation, and whether the sample is identical to the production sheet.
- Method seen
- Not a test: a written statement from the supplier.
- Why it matters
- Data from a prototype lot says little about a delivery six months later.
- Kora status
- Not published
Under research, not yet verified · Method numbers and third-party values come from search listings and summaries read on 2026-10-20. Confirm editions before quoting. None of these values belong to Kora.
How to log the answers
- One row per card, one column per supplier.
- Record method, edition, lab, date and lot beside each number.
- Mark blanks as blanks. Do not average across different methods.
- Ask the same questions of Kora; see its current status on the Kora status page.
