Methodology
Every figure on a passport is calculated by a fixed rule, from data the brand entered itself. This page writes down the rules, the factors used, and where those factors come from.
This page is available as a file. The file names the factor library version in force when it was taken, together with the date, so a copy already attached to a review file still says the same thing after the library version rises.
How each figure is calculated
- Recycled material
- The weighted average of recycled content across every material, multiplied by the product weight to give the kilograms.
- Textile waste avoided
- Every kilogram of recycled material counts one for one as virgin material not used. Written with a ± sign because it is an estimate.
- Material carbon footprint
- The weight of each material multiplied by its emission factor, then summed. The scope is materials only, to the factory gate, not transport, sewing, use, or disposal. If even one material has no sourced factor, the figure is not shown at all rather than summed in part.
- Circular potential
- Rule-based points: single-material cloth, the recycled share, the presence of care and repair guidance, and the parts that have a return path of their own. A blend of three or more fibres subtracts points because it is harder to recycle. The result reads as Low, Medium, or High.
Evidence tiers
Every material or process claim carries its evidence tier. The absence of a certificate is not a shortfall: certificates cost money, and the farmers and makers upstream rarely hold them. What is documented is stated with confidence.
- CertifiedA third-party certificate, with its validity tracked.
- DocumentedBatch records, photographs, or statements from farmers and makers.
- Self-declaredThe brand's own account, with no supporting document.
Emission factors
Library version v2.0-idemat-2026RevB1.
Idemat 2026 RevB1 (Stichting Sustainability Impact Metrics, a TU Delft spin-off), IPCC 2021 GWP100 carbon footprint, cradle-to-gate, per kg of material. Each fibre factor carries its own Idemat process code. Two factors, recycled cotton and ramie, are absent from Idemat and come from published studies cited on those rows. Used under the 2026 EULA. Data from www.ecocostsvalue.com.
| Material | kg CO2e / kg | Source family |
|---|---|---|
| Acrylic | 5.1 | Idemat 2026RevB1, A.140.01.101.240814, acrylic fibres |
| Bamboo viscose | 1.5 | Idemat 2026RevB1, A.140.01.118.230701, viscose production; applied to bamboo viscose on the assumption of the same process |
| Cotton | 0.9 | Idemat 2026RevB1, A.140.01.106.230701, cotton fibre trade mix (without global sea transport) |
| Organic cotton | 0.4 | Idemat 2026RevB1, A.010.08.102.230701, organic cotton, India |
| Recycled cotton | 0.2 | Esteve-Turrillas & de la Guardia 2017, Resources, Conservation and Recycling 116:107-115, as summarised in VTT-R-00941-22 Table 2; mechanical cotton recycling, cutting and shredding, Spain; excludes collection and sorting, and excludes carding |
| Elastane | 3.7 | Idemat 2026RevB1, A.140.01.107.230701, elastane (polyurethane) pellets |
| Hemp | 0.9 | Idemat 2026RevB1, A.010.08.117.250214, hemp fibres, USA (12% moisture content); region United States |
| Jute | 3.7 | Idemat 2026RevB1, A.140.01.109.230701, jute fibre incl. degumming, market mix |
| Leather | 15.2 | Idemat 2026RevB1, A.010.02.101.240318, leather, chrome tanning, hides from Argentina; used for leather with unspecified tanning |
| Linen | 1.4 | Idemat 2026RevB1, A.140.01.121.230701, flax fibres for spinning linen |
| Recycled nylon | 4.6 | Idemat 2026RevB1, A.130.03.109.230701, polyamide (nylon) chemically upcycled |
| Nylon | 5.5 | Idemat 2026RevB1, A.140.01.114.230701, nylon pellets |
| Recycled polyester | 0.4 | Idemat 2026RevB1, A.130.03.093.250411, rPET mechanically recycled in China, ex transport |
| Polyester | 2.1 | Idemat 2026RevB1, A.140.01.115.230701, polyester (PET) pellets |
| Ramie | 1.8 | Dong, Xian & Yi 2018, Aerospace 5(3):81, DOI 10.3390/aerospace5030081, CC BY 4.0; ramie fibre after carding, functional unit 1,000 kg of fibre, cradle-to-gate, China; excludes spinning (yarn is 3.79 in the same paper); includes biogenic carbon uptake at the cultivation stage, so it is not treated identically to the Idemat rows |
| Viscose rayon | 1.5 | Idemat 2026RevB1, A.140.01.118.230701, viscose production |
| Wool | 61.0 | Idemat 2026RevB1, A.140.01.119.230701, wool from Australia, transported to Rotterdam |
A material not yet in this table can still be recorded on a passport, its composition renders as usual, only the carbon figure does not. We would rather show no figure than show one we cannot source.
Where the factors come from. Most of the public inventory libraries available today are European and North American averages. The Indonesian electricity grid factor from ESDM is the only local data point we use. That means the material carbon figures here are screening-level estimates built on foreign averages, not measurements of an Indonesian supply chain. We write it down because a figure whose source its reader does not know cannot be checked by anyone.
Where the material figures come from
A provisional library uses opening figures that carry no source to cite; a sourced library uses figures from a published dataset, and every factor carries its own source and process code. When the library changes, what changes is the basis of the calculation, not the product.
Different LCA libraries give different figures for the same material, and the spread can reach threefold. What we show is the figure from one library that can be cited, not the only figure that exists. The source and version are written on every block, so any figure here can be traced back to its dataset.
As an independent comparison, Dahlbo et al. 2017 record cotton at 2.62, polyester at 3.10, and viscose at 3.43 kg CO2e per kg; the library in force here gives 0.94, 2.05, and 1.50 for the same materials. We do not average the two, and we do not pick the higher figure to sound more careful: an average of two libraries with different system boundaries is a figure with no source at all.
Libraries that have been in force
- v2.0-idemat-2026RevB1 · published 4 September 2026 · in force nowIdemat 2026 RevB1 (Stichting Sustainability Impact Metrics, a TU Delft spin-off), IPCC 2021 GWP100 carbon footprint, cradle-to-gate, per kg of material. Each fibre factor carries its own Idemat process code. Two factors, recycled cotton and ramie, are absent from Idemat and come from published studies cited on those rows. Used under the 2026 EULA. Data from www.ecocostsvalue.com.
Material factors from Idemat 2026 (Stichting Sustainability Impact Metrics), data from www.ecocostsvalue.com
- v1.0-provisional · published 13 August 2026The figures in this table are still provisional. Every factor will carry a citable source before public launch; until then the numbers here are used as early estimates and marked as such.
What is not scored
- No letter grade on the passport. We calculate a materials grade for the brand inside its own dashboard, so the brand knows where it stands and what would move it. That letter never appears on a public passport. The reason: the rest of the passport states facts that can be checked, while a letter ranks a brand against a scale we drew up ourselves, and that scale would stand on the foreign average factors we just described. If you see a letter grade on another platform's passport, it is worth asking which factors it used and where its band boundaries are published.
- Certification does not set the value. A certificate is evidence, not virtue. Scoring it would penalise exactly the upstream that cannot afford the gate.
- Origin and import distance do not set the value. Transport is a fact that belongs in the carbon footprint, not a judgement about a place.
- These figures are not third-party verified. Our calculation calculates; it does not certify. A figure becomes verified only through third-party review.
Address and resolution
The figures can change. The address cannot.
The figures on a passport can change as its evidence improves. The passport's address cannot. This section writes down the address rules, because the address printed on a hangtag is the one part of this system we cannot correct after it ships.
The address form
Every passport lives at p.mula.asia/{brand-code}/{slug}. That subdomain is used for nothing else: not marketing, not the application, not redirects. Marketing routes may be rearranged; passport routes may not.
A slug is editable until first publication and permanent thereafter. An address that can still be changed after it is printed is a broken QR waiting to happen. Slugs are unique within each brand's namespace and checked against a reserved-word list.
The address also does not change when the state of the passport changes. A passport that goes inactive, that becomes active again, or that moves to a different plan stays at the same address. What changes is what renders there, never where the code points.
The address is deliberately short. Every character adds modules to its QR, which densifies the code, lowers legibility on a small tag, and leaves less room for the mark at the centre.
One printed form, always
Only the path above is ever printed. The canonical path /01/{GTIN} is answered at the same address as a redirect alias, from day one, for machines: customs systems, retailer systems, recycler scanners, and registry lookups. Those systems query the canonical path and do not scan hangtags.
That redirect is temporary rather than permanent, and that is deliberate. The passport address is permanent, while the GS1 number pointing at it is data a brand can edit. A permanent redirect would sit in browser and proxy caches longer than the fact behind it survives, and a cache cannot be recalled any more than a printed tag can. The canonical path is also kept out of search indexes, so that it does not slowly become a second address.
A number with a wrong check digit and a number that points at no passport are answered differently. The first is a malformed number, the second is a question with no answer, and the system on the other side needs to know which one it has to fix.
A brand that gives each individual piece its own identity uses the same address with one more level of depth, p.mula.asia/{brand-code}/{slug}/21/{serial}. That is one address form with two depths, not a second scheme.
Three reasons the GTIN path is never printed
- A GTIN is per variant, while a passport is per product. A shirt in five sizes carries five GTINs against one passport. Printing the GTIN path forces a choice between five passports and one number that is factually wrong on four tags out of five.
- Ownership of a number cannot be verified. The check digit proves the number is well formed, not that it belongs to the brand using it. A typo becomes permanent at print.
- Two printed schemes in the world means two code paths and two failure modes, against a constraint that is really working hours.
Product number (GTIN)
Optional, at variant level. The check digit is validated on entry. Never required, never a gate on publication.
Mula never issues a number and offers no control that generates one. An invented thirteen-digit number will eventually collide with a real product, and by then it is printed.
When present, the GTIN renders small in the product details line beside the SKU, and always travels in machine-readable output and in the export pack. When absent, nothing renders: no empty field, no note saying the number is missing, no gap indicator. A brand without GS1 membership is not an incomplete brand, and rendering its absence would let a paid credential back into the passport through the side door.
Where we stand with GS1
Mula passport addresses follow the GS1 Digital Link URI structure.
That is the only form of the statement we use, and we do not use a stronger one. Mula is not a GS1 member. Mula is not GS1 certified, not declared conformant by GS1, not registered with GS1, and not a GS1 partner. We do not display the GS1 logo. Following the structure of an address is a technical choice; membership and conformance programmes are something else, and we are not in them.
Brands using Mula do not need to be GS1 members either.
The European Union registry
The EU DPP registry has been running since July 2026. It is a directory that indexes identifiers and points at passport data; it is not a data host. No product registration duty falls on textile brands until the textiles delegated act triggers it. When it does, registration requires a verified economic operator, which for Indonesian brands runs through their EU importer or authorised representative, not through Mula.
