There's a factory in Asia that uses only a single litre of water to make a pair of jeans. That's 346 litres less than Levi-Strauss estimated it took to make a pair of its jeans in 2015. The manufacturer in question does not want to tell anyone about its groundbreaking water-conserving techniques - not even the companies it supplies. It is one of many practicing secret sustainability", whereby innovations are silently enacted and kept from the rest of the industry. This phenomenon is not limited to the clothing industry. Why would firms spearheading sustainable practices not publicise their good work? It's a question that puzzles Professor Steve Evans ... at Cambridge University's Institute for Manufacturing, who suggests that such examples are widespread. He believes this stems from a common perception that there must be some kind of downside to the introduction of sustainable practices: either a reduction in product quality, or an increase in the price of manufacturing, or both. Companies and consumers seem unable to accept that sustainability does not have to cost more to create an equally good product. This is despite an increase in evidence that actively investing in sustainable practices helps business thrive. An example is provided by the Dow Jones Sustainability Indices, a series of benchmarks assessing the sustainability of companies around the world. Research has repeatedly shown that those at the top end of the benchmark outperform those at the bottom.