LOS ANGELES, United States — Hiding inside a parking lot in LA's gentrifying, warehouse-filled Arts District stand huts made of walls of wavy white aluminium and slats of plywood, the classic Levi's logo spraypainted right across the front. Within one of these makeshift buildings stands a magical machine, where guests are invited to design the elusive perfect jean.

A pair of classic 501s, rendered in gleaming medium-wash blue, are laid out on a flat grey surface. Before you know it, a laser is delicately scything away cotton from the front of the denim, wearing it down to look it has been sanded and stonewashed and, well, used. A dust bowl of blue smoke — fibres — floats up, creating little pink sparks where the beam meets the fabric.

This is Levi’s F.L.X. technology — a laser-powered process that allows consumers to customise and personalise a unique distressed finish on their jeans. The denim stalwart's newest service is emblematic of the ever-changing denim industry, driven by innovation and a greater focus on sustainability as demand continues to grow. By giving consumers the opportunity to design exactly what they want, laser distressing could be used to create the thousands of finishes currently on offer through traditional methods like sanding. What's more, the environmentally friendly procedure steps in line with the industry's growing preference for sustainable practises, such as using recycled water and recycled fabrics.

Denim sales in the US grew 4 percent in 2016 and were forecast to sustain that growth last year, according to NPD Group. Levi’s itself saw a 17 percent year-over-year increase in revenue in the second quarter of 2018, the company announced in July, while earnings before interest and taxes (EBIT) rose 15 percent.

Jeans reached more than $40 billion in global sales in 2016, according to P&S Market Research, and by 2023, the denim market is expected to exceed $87 billion.

Traditionally, labourers use chemicals and sanding blocks to create fades and finishes on a pair of jeans. It’s a process that can stretch over 20 separate steps, and can involve large amounts of water and over 1,000 types of chemicals, said Bart Sights, vice president of technical innovation at Levi's Eureka Innovation Lab. Customisation — especially on a per-customer basis — is difficult because the process is so labour intensive.

At Levi’s invite-only Los Angeles customisation studio, which opens on Aug. 8 for 10 weeks, consumers can pick patterns of distressing — rips, fades, etc. — on an iPad. These unique finishes are then created on a blank pair of jeans with infrared lasers operated by a digital craftsman in the studio. The laser process takes less than three minutes, and after a final hour-long wash, the jeans are ready to be taken home. The company has been testing this technology behind-the-scenes for two years, according to Sights.

Lasers cut out much of the manual labour and nearly all of the chemicals (though a few dozen are still used, mainly in the washing process), Sights said. The technology also has major cost-saving potentials. Levi's currently offers 2,000 variations of denim finishes a year, or 1,000 each season. If the company could make products on-demand à la F.L.X., it could reduce the products it needs to carry at any given point, therefore reducing inventory risk drastically.

The F.L.X. capability will be rolled out to select Levi’s stores in spring 2019 and fulfilled from three distribution centres across the US, Europe and Asia.

The F.L.X tech isn't Levi's first foray into customisation. In the 1970s, the brand hosted customisation competitions. In 2012, Levi's launched its Lot 1 studios, which sell made-to-order jeans in New York, London and San Francisco. Levi's has also launched dozens of tailor shops in retail locations that allow customers to add patches, pins and chain-stitch embroidery to their jeans.

Laser distressing is also not new to Levi's or the industry as a whole. It emerged in the 1980s to produce decorative patterns and logos, said Fabio Adami Dalla Val, the show manager at Denim Première Vision, a company that organises shows and events for the fashion and textile industries.

More recently, denim makers have faced growing pressure to reduce their environmental footprint, as more brands and consumers demand sustainable fashion. Jeans require enormous amounts of water to produce — up to 1,800 gallons needed to grow and harvest the cotton for a single pair — with factories requiring water for various washing and dyeing stages.

Denim brands such as Levi’s and G-Star Raw have already made strides in reducing harmful water usage by nearly 100 percent. Everlane researched denim production for years before launching its jeans category in fall 2017, after finding a jeans factory in Vietnam that recycles 98 percent of its water.

"The denim industry was one of the first movers in which we've seen new innovations and new machines that can reduce resources," said Eva Kruse, chief executive and president of the Global Fashion Agenda.

Laser technology reduces worker exposure to potentially hazardous chemicals, but comes with trade-offs, including increased electricity usage, Adami Dalla Val said.

A truly sustainable process isn’t about any single step but rather the entire production process, he said. For example, denim manufacturers in Italy are required to recycle water and purify it so it’s drinkable. Jeans produced in sub-Saharan Africa don’t face the same requirements, even though the strain on water supplies may be greater.

“[Lasers] are good for ethical considerations but it’s not really reducing [the strain] on the environment,” he said. Ultimately, though, Levi's' new feature is a shot at diminishing both waste and inventory.

Additional reporting by Lauren Sherman.

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