Crust Leather Specification: What to Put in Your Purchase Order

5 days ago

6 min read

Updated: 20 hours ago

A crust leather specification is the written standard your supplier must ship against. Updated November 2026: for importers buying crust from India it should fix the animal and tannage, process state, selection, thickness range, area measurement, ISO test limits and packing. For chrome footwear crust, ISO 20940:2021 is the reference specification.

Key Takeaways

ISO 20940:2021 sets requirements, test methods and sampling for crust full chrome upper leather for footwear; ISO lists it as under systematic review (as of November 2026).
Write thickness as a range measured to ISO 2589 at ISO 2418 sampling positions, never as a single figure.
Area of dry leather is measured under ISO 11646; agree the unit (sq ft or sq m) and the tolerance before the order is confirmed.
India's export duty on crust leather has been nil since 2 February 2025 under Notification 03/2025-Customs (as of November 2026).
EU REACH limits chromium(VI) to 3 mg/kg in leather articles that touch the skin, so ask for an ISO 17075 Cr(VI) result on crust bound for European products.

Why does crust leather need its own specification?

Because crust has no finish coat to hide variation. Crust is tanned, retanned, dyed, fatliquored and dried but not finished, so its feel, dye penetration and strength come straight from the wet-end recipe.

A finisher in Europe, Vietnam or Africa will spray, press or emboss that crust in its own plant. If the lot arrives softer, thinner or more open-grained than the approved counter-sample, the finish behaves differently and the problem is found only after the leather is in production. A written specification ties every lot to the counter-sample and gives both sides an objective way to accept or reject it. For the basics of crust versus wet blue and finished leather, see our guide to choosing a crust leather supplier in India.

What should a crust leather specification include?

At minimum, eleven fields. The table below shows what to state in each one and why it matters to the buyer.

Field	What to state	Why it matters
Raw material	Cow, buffalo or goat; whole hide, side or skin	Fibre structure and usable area differ by animal
Tannage	Full chrome, vegetable, or chrome-free (wet white)	Decides finishing behaviour, heat resistance and compliance claims
Process state	Retanned, dyed through or surface-dyed, fatliquored, milled or not	Controls softness, colour on cut edges and how the finish anchors
Grain	Full grain, corrected (buffed) grain or split	Sets which finishes and embossing are possible
Selection	Grade names exactly as on the supplier's selection sheet	Prevents disputes over defects per hide
Thickness	A range, e.g. 1.2 to 1.4 mm, measured to ISO 2589	Downstream splitting or shaving costs money and area
Area and size	Unit, measuring method, average size per piece	You pay per square foot or metre
Colour	Physical reference swatch plus light source for matching	Crust colour shifts once finished; the reference must be agreed
Physical tests	Methods and limits (see next section)	Proves the lot will survive lasting, flexing and wear
Chemical tests	Cr(VI), formaldehyde, azo dyes, pH	Required for EU, UK and US brand compliance
Packing	Bundle size, wrapping, moisture control, labels per bundle	Prevents mould and mix-ups in transit

Which ISO test methods belong in a crust purchase order?

Name the test method, not just the property. ISO 20940 builds its requirements on standard ISO leather methods and sets different minimum strength values for bovine, goat and sheep crust, so state the animal and quote the limits from the edition you use.

Sampling location: ISO 2418. Results only compare if samples are cut from the same zone of the hide.
Thickness: ISO 2589.
Tensile strength and elongation: ISO 3376.
Tear load (double edge): ISO 3377-2. This is the key test for stitched footwear uppers.
Distension and grain crack: ISO 3379 (ball burst), which predicts cracking on the lasting machine.
Flex resistance: ISO 5402-1.
pH and difference figure: ISO 4045.
Chromic oxide content: ISO 5398-1, which also confirms a chrome-free claim.
Chromium(VI): ISO 17075-1 or -2. Formaldehyde: ISO 17226-1. Azo colourants: ISO 17234-1.

For European end products, the chromium(VI) limit of 3 mg/kg in leather articles in contact with the skin comes from Commission Regulation (EU) No 301/2014 (REACH Annex XVII, entry 47). Crust that already tests low gives the finisher a margin. Our overview of leather testing standards for importers explains which lab reports each market expects.

How should thickness and area be written into the order?

As ranges with a stated method and tolerance. Thickness in crust varies across the hide, so a single figure is unenforceable.

For thickness, give the range (for example 1.2 to 1.4 mm for a men's upper), say it is measured to ISO 2589 at the ISO 2418 position, and agree how many out-of-range pieces per bundle you will accept. For area, ISO 11646 specifies how to measure dressed and other dry flexible leathers. State whether you buy in square feet or square metres (1 sq m = 10.764 sq ft), whether the supplier's machine measurement is final, and the tolerance between the invoiced and your re-measured area. Ask for a tally sheet that lists the area of every piece in each bundle.

What changes for vegetable-tanned or chrome-free crust?

ISO 20940 covers full chrome crust only, so for vegetable or chrome-free crust the buyer and supplier must agree the limits themselves. Use the same ISO methods, set strength limits from your approved counter-sample, and add a chromic oxide result (ISO 5398-1) if the product will be sold as chrome-free. Declare the tannage on the purchase order and the commercial invoice so any sustainability or "chrome-free" claim can be traced back to the lot.

What should importers check before crust ships from India?

Five checks catch most problems before the container is sealed.

Approve a counter-sample and keep one signed piece at each end.
Run a pre-shipment selection check against the agreed grade sheet.
Take thickness readings on a sample of pieces from several bundles.
Match the tally sheet to the commercial invoice area.
Confirm packing and moisture control, and the HS code on the documents.

Our guides on HS codes for crust leather exported from India and preventing mould in leather shipments cover the last step in detail. On the Indian side, crust leaves with nil export duty since 2 February 2025 (Notification 03/2025-Customs, as of November 2026); import duty is set by your own country's tariff.

How Sanwas International works with crust and hides buyers

Sanwas International is an LWG-certified OEM and private label leather manufacturer based in Jalandhar, Punjab, India, producing footwear, outerwear, furniture leather and hides for brands in India and worldwide.

Within its leather hides supply line, Sanwas International supplies cow, buffalo and goat hides in full-grain, nubuck, suede and vegetable-tanned finishes, sorted into Cutting 1, Cutting 2, BB and Reject selections and Super, Extra Heavy, Heavy and Medium weight classes. Hides can be machine-cut or hand-cut to your specification and supplied in custom colours, with AQL inspection before export shipping. You can request sample hides for approval before bulk, and our leather materials expertise page explains the leathers we work with. Send your crust or hides specification for a quote.

Frequently Asked Questions

What is ISO 20940 and does it apply to all crust leather?

ISO 20940:2021 is the ISO specification for crust full chrome upper leather used in footwear, covering requirements, test methods and sampling. It does not cover vegetable-tanned or chrome-free crust, or crust for upholstery and garments. For those, buyers set their own limits using the same ISO test methods.

I run a shoe factory in Vietnam and want to buy crust leather from India. What should my purchase order say?

State the animal, tannage, process state, grain, selection grade, thickness range, area unit and tolerance, colour reference, ISO test methods with limits, and packing. Attach a signed counter-sample reference. Add the Incoterm, payment terms and the documents and test reports you need for customs clearance.

How do I make sure the area on my crust leather invoice is accurate?

Ask the supplier for a tally sheet listing the measured area of each piece in every bundle, and agree in the order that measurement follows ISO 11646. Re-measure a sample of bundles on arrival and compare against the tally. Agree in advance the tolerance beyond which a credit note applies.

Is there an export duty on crust leather shipped from India?

No. India's export duty on crust leather was reduced to nil from 2 February 2025 under Notification 03/2025-Customs, and it remains nil as of November 2026. Import duty and VAT in your own country still apply and depend on the HS code and any trade agreement.

Which Incoterm should an overseas tannery use when importing crust leather from India?

FOB at an Indian port suits buyers who have their own freight forwarder, while CIF puts sea freight and insurance with the supplier up to your port. EXW leaves export clearance in India to the buyer, which is usually harder for overseas companies. Whichever you choose, write the named port or place next to the Incoterm.

Writing a Crust Leather Specification? Request a Quote

Tanneries, finishers, footwear and leather-goods factories, traders and importers can send their crust or hides specification to Sanwas International for a quote. Share the leather type, thickness, selection, target quantity, destination country or Indian city, preferred Incoterm and target delivery date. Sanwas supplies buyers across India and exports to Asia, Europe, North America, Africa and Australia.

Include these details in your enquiry: