Not a single global fashion brand is really transparent about its supply chain.This is among the findings of Fashion Revolution, a campaign group, which reviewed and ranked 100 of the biggest global fashion and apparel brands and retailers. Out of a possible 250 points Adidas and Reebok scored highest with 49 points, Marks & Spencer and H&M scored 48 and Puma, Banana Republic, Gap and Old Navy score 46 points.

These brands represent a cross section of market segments including high street, luxury, sportswear, accessories, footwear and denim from across Europe, North America, South America and Asia. They were asked to disclose information about their suppliers, supply chain policies and practices.

A little more than 30 of the 100 brands publish their supplier lists - at least at the first tier where clothes are typically cut, sewn and trimmed. This year 14 out of the 100 brands are also publishing their processing facilities where clothes are dyed, printed, laundered and otherwise finished at an earlier stage of production. But no brand publishes its raw material suppliers, so there is no way of knowing where cotton, wool or other fibers come from or who produces them. Wholesalers, agents and distributors play profitable roles in the clothing industry that the public doesn't really see.