← Frank Fiber: Thread Detective

Methodology & sources

1. What we calculate

Given a fibre composition, a "Made in" country and your location, we estimate: (a) a typical multi-leg transport route (fibre origin → fabric/garment making → export port → transshipment → your region), (b) CO₂e for those freight legs, and (c) context — how that freight compares with a typical garment's full lifecycle climate impact.

2. Freight emission factors (well-to-wake)

• UK DESNZ/DEFRA GHG conversion factors 2025 / 2026 ("Freighting goods" + "WTT" sheets summed; air factor includes non-CO₂/radiative-forcing effects unless stated).
• GLEC Framework v3.1 (Smart Freight Centre), the implementation of ISO 14083:2023.

3. Lifecycle context

• Quantis, Measuring Fashion (2018): distribution ≈ 1.3% of apparel value-chain GHG; dyeing & finishing alone 36%.
• Mistra Future Fashion / Sandin et al. (2019): freight ≤3% of full lifecycle; production ≈80%; consumer's own shopping trip ≈11% (separate item).
• Devera (2025) t-shirt benchmark: transport 2.1%; raw materials + manufacturing 83.6%.
• Lifecycle band shown = garment weight × 10–27 kg CO₂e/kg, spanning published cradle-to-grave anchors. It is deliberately wide.
• The exception: air freight. 34–110× ocean freight per tonne-km (like-for-like sources). Air-freight-heavy retail breaks the "freight is small" rule — Shein's reporting puts transport near 38% of its climate footprint.

4. Route inference

• Fibre origins from trade data (UN Comtrade, USDA FAS): e.g. cotton in "Made in Vietnam" garments is ~47% US-grown; Bangladesh's cotton is ~41% West African; polyester is overwhelmingly produced in China (~57–59% of world fibre supply is polyester).
• Export ports and transshipment hubs per country from published port statistics (e.g. Chittagong → Colombo transshipment; Vietnam via Cat Lai/Cai Mep; Singapore ≈ 1/5 of world transshipment).
• Sea distances: published port-to-port figures where available; otherwise great-circle × 1.35 routing factor (land: × 1.25) — flagged "est." per leg.
• Mode-split and air-share assumptions follow the published defaults of Ecobalyse, France's official textile environmental-cost engine (MIT-licensed; dataset under Licence Ouverte 2.0). Final delivery leg assumed 500 km domestic trucking.
• We assume yarn/fabric is made in the "Made in" country unless trade data says otherwise (e.g. Cambodia sews fabric mostly woven in China). Real chains vary — that's why everything is an estimate.

5. Where the raw material came from — the worst→best odds

A garment's fibre can rarely be traced to one field or well: crude oil, cotton and wood pulp are blended and traded on global markets. So we never claim an origin — we show the probability it came from each place, ordered worst → best on a stated, material-specific environmental axis. These are illustrative, sourced approximations, not a trace of your specific garment.

• Crude oil (polyester, nylon, acrylic, elastane). Probability = each country's share of China's crude-oil imports (China spins most of the world's polyester), 2024–25 average — EIA and Columbia CGEP. Volumes labelled "Malaysia" are a documented transshipment cover for sanctioned Iranian and Venezuelan crude (MEES), so we split them out. Worst→best axis = upstream carbon intensity (gas flaring and heavy/unconventional oil are worst): Masnadi et al., Science 2018 / Stanford (≈3.3 g CO₂eq/MJ Denmark to 20+ g Algeria; Saudi crude is low because it flares little).
• Cotton. Probability = share of world cotton production/exports, 2024–25 (USDA FAS; OEC). Worst→best axis = environmental + documented labour risk: drained-river irrigation and forced-labour findings worst (Aral Sea; US UFLPA import ban on Xinjiang cotton, 2022; ILO on Central Asia), rain-fed / water-efficient / no-forced-labour best (Better Cotton; Australian water-efficiency).
• Wood pulp (viscose, modal, lyocell). Probability = indicative geography of dissolving-pulp feedstock. Worst→best axis = ancient- and endangered-forest / deforestation risk (Canopy's CanopyStyle audits): documented rainforest and peatland clearance worst (Mongabay/NBC on Indonesia), certified plantation and closed-loop best (FSC/PEFC; Lenzing TENCEL™). Bamboo pulp is treated separately (overwhelmingly Chinese; Sichuan).
• Important: the "worst" end of every axis is an environmental (and, for cotton, documented labour-rights) measure — not a political or blanket human-rights ranking of a country. Each item is a sourced, disclosed risk factor, and the panel states its axis in plain language.

6. Fibre naming (why we may rename what your label says)

"Bamboo" is not a legal fibre name for regenerated fibre in the US (FTC, 16 CFR Part 303), EU or UK (Reg. 1007/2011): such fibre must be labelled rayon/viscose, modal or lyocell. We render it as "viscose/lyocell made from bamboo" and say so. Only mechanically-processed natural bamboo may be called "bamboo".

7. Who built this

Frank Fiber: Thread Detective is an independent tool — it doesn't sell clothes and isn't owned by a clothing brand. Its worked example is bmbū, a brand that volunteered its full chain through the same engine, city-level, and holds itself to the same wording rules (its fibre is "lyocell made from bamboo", its thread is "made from TENCEL™ lyocell fibre produced in Thailand"). This tool never scores one brand against another, and it will tell you that sea-freight distance is a small part of the story even when a chain spans three countries.

8. Boundaries & what we do not do

• Freight figures are well-to-wake; the lifecycle band is cradle-to-grave from the cited anchors. We never mix methodologies inside one number.
• No "carbon neutral"/"net zero"/"eco-friendly" outputs — ever (EU Directive 2024/825; UK CMA Green Claims Code; FTC Green Guides).
• No offsets, no scores against named brands, no data about your garment we didn't tell you we inferred.

Questions or corrections: hello@frankfiber.com