Overview - EN ISO 2588:2014 (Leather sampling, gross sample size)
EN ISO 2588:2014 (ISO 2588:2014) specifies a standardized method for drawing whole pieces of leather from a lot to form a gross sample. Published by IULTCS in collaboration with CEN/TC 289, the standard applies to all kinds of leather regardless of tannage. It defines how many whole leather pieces to select depending on lot size and the testing purpose, and it sets out basic requirements for truly random selection and sampling reporting. Note: marking and storage of the gross sample are not covered by this document.
Key topics and requirements
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Scope: sampling of whole leather pieces to form a gross sample applicable to any type of leather.
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Definitions: terms such as lot (batch), gross sample, and item (a whole piece of leather) follow ISO 3534-2 interpretations.
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Minimum sample sizes: the standard gives the minimum number of items in a gross sample depending on lot size and whether testing is non‑destructive or destructive:
- Lot size 1–10: Non‑destructive = 2, Destructive = 1
- Lot size 11–50: Non‑destructive = 3, Destructive = 2
- Lot size 51–100: Non‑destructive = 4, Destructive = 3
- Lot size 101–500: Non‑destructive = 5, Destructive = 4
- Lot size > 500: Non‑destructive = 10, Destructive = 5
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Sampling method: selection shall ensure truly random sampling (for example, numbering pieces and selecting by random number tables).
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Sampling report: must include reference to ISO 2588, lot identification and size, number of items selected, any unusual observations, and any deviations or alternative procedures used.
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Flexibility: Clause 4 allows parties to agree a different procedure or adapt numbers depending on test reliability, property variation, and testing error.
Practical applications
- Quality control in leather manufacturing and finishing operations.
- Incoming inspection of leather lots by tanneries, converters, footwear and leather goods manufacturers.
- Test laboratories preparing gross samples for standardized testing (physical, chemical, or fastness tests).
- Procurement and acceptance sampling during trade to ensure representative sample sizes for contract testing.
Who uses this standard
- Leather technologists, quality managers, laboratory technicians, procurement and inspection teams, and standards bodies involved in leather testing and trade.
Related standards
Using EN ISO 2588:2014 helps ensure consistent, defensible leather sampling practices that support reliable test results and transparent reporting in manufacturing and trade.
