The weather during Milan Design Week is famously unpredictable. Sitting on the edge of spring – the event takes place over six days every April – occasionally it’ll be T-shirts, shorts and negronis in the blazing heat, while other years, it’ll be a complete wash-out. This year it was, appropriately, a tale of two climates. The first three days were sunny, followed by days of miserable rain, which was a neat metaphor for the festival itself. While there was jubilance and decadence in the many maximalist displays on show, there was also a deeper, slightly darker undercurrent that was equally apparent. This felt new – 2019 was the year that Salone del Mobile had something to say. Not just on style, but on sustainability and, put simply, the sheer volume of stuff in our lives.

The 1970s trend began in subtle earnest last year with the popularity of beige and brown tones but 2019 saw its whole-hearted embrace. Mr Raf Simons brought back corduroy fabrics for his fabric collection with Kvadrat, Danish brand Montana re-issued the Pantonova steel-wire sofa designed by Mr Verner Panton, which featured in 1977’s The Spy Who Loved Me, while Milanese firm Dimore Studio recreated the apartment of design icon Ms Gabriella Crespi in its show. It was an explosion of bamboo and cane furniture, burgundy shag pile rugs, leopard-print walls and, in one room, mounds of white sand that would have put the loos at Studio 54 to shame.

That the recent move towards maximalism has taken up comfortable residence next to the 1970s revival is, in some ways no surprise. Despite its superficial brassiness and tasteless glamour, it was a decade attached to earthy colours such as olive green and brown, natural materials (well, faux fur and animal print in this case) and handicrafts (rattan, anyone?). There’s so much talk about how we yearn for real-life experiences in the digital age: what era provides a more experiential experience than the mad 1970s? Its boldness and bad tastes brilliantly jar with the glossy digitalised minimalism of modern life in 2019 and this was ubiquitous at Salone.

The presence of digital companies such as Google, Instagram, WeWork and Airbnb have crowded Milan Design Week in recent years. By strong contrast, furniture and forms that owe inspiration to the natural world – far, far away from anything vaguely technological – was a striking theme in 2019.

“As humans, we crave a connection to the natural world and are increasingly starved of it,” says New York-based designer Ms Anna Karlin, who debuted her latest collection of gentle, organically-shaped furniture in Milan, including lights that look like large glowing pebbles. “Spaces can help us overcome this.”

The sentiment was shared by US brand Apparatus, which presented embroidered hand-finished pendant lights and cabinets made of burl and eel skin at its moody showroom in Milan. The materials and craftsmanship is a missive to our connection with the natural world. “These materials recall a time and place in the past,” says creative director Mr Gabriel Hendifar. “I think of them as creating a kind of historical fantasy.”

This trend was also picked up in the first collection by Mauritius-based brand Cypraea, who showed a table made of lava stone and a cabinet inspired by waterfalls. At the Perfect Darkness installation, a show apartment designed by Msses Josephine Akvama Hoffmeyer and Elissa Ossino, the duo used organic touch points such as ceramics, wood and textiles to demonstrate our human need for the natural world in interior spaces.

Exhibiting interesting processes instead of unnecessary product was a key theme in Milan this year. In the shadow of “peak stuff” – the now infamous declaration made by the former Ikea chief sustainability officer in 2016 – many designers are thinking about how we make things instead of what we consume.

The new material display by Rotterdam’s Het Nieuwe Instituut at the Alcova exhibition brought together 15 projects that focused on material innovation. Ms Sanne Visser makes use of the 6.5 million kilograms of human hair that enters the waste stream in the UK each year to produce rope. Ms Ekaterina Sememova makes pottery out of waste milk, while Studio Basse Stittgen has developed a material made from cow’s blood, a waste product of the food industry.

With smart ideas and fascinating processes, the next challenge is turning them into viable materials that can be used industrially, such as the tile collection ExCinere – meaning “from the ashes” in Latin. The glazed tiles were presented by Dzek, a London-based firm that develops original architectural materials (it was responsible for the wildly popular terrazzo by designer Mr Max Lamb a few years ago). Three years in the making, the tiles are made using volcanic ash from Italy’s Mount Etna and have been developed by Amsterdam-based firm Formafantasma. Beautiful, sustainable and logical.

Plastic has deservedly become one of the most important issues facing the design industry and many brands have taken up the challenge of rethinking how we use it in our homes. Changing perceptions of “recycled” plastic furniture has been a theme at Salone in recent years, but this year a number of pieces showed how it can well and truly enter the mainstream. For some brands, it is not a one-off project, but a given to expect that furniture is part of a circular recycling economy.

Danish design brand Mater presented a reissue of a chair designed by icons Mr Jørgen Ditzel and Ms Nanna Ditzel in 1955 as part of its Ocean Collection. Like all it pieces, it is made using ocean plastic waste. Elsewhere, British design duo Barber & Osgerby presented the On & On collection of two chairs and a stool for US manufacturer Emeco. They are made of recycled PET bottles and can be endlessly recycled. Crucially, both examples are classic, timeless pieces of design that should be used, not just showpieces made for Salone.

“Waste plastic is now on everyone’s lips,” says Mater CEO and founder Mr Henrik Marstrand. “But it is still very important that the designs that go into production have all the needed elements such as being timeless, alluring, high quality and comfortable for everyday use. This is where our design-driven industry can make a mark.”

Fashion houses presenting during design week is nothing new: Louis Vuitton, Cos and Hermès are as much fixtures here as B&B Italia or Minotti. While the fashion brands can always be counted on for some beauty, this year they sought to show something more thought-provoking.

Mirroring what was going on across Milan, material innovation struck a chord with Cos, which collaborated with London-based architect Mr Arthur Mamou-Mani on a 3D-printed pavilion made of biodegradable bioplastic. Green was also a hot topic at Jil Sander. Under the creative direction of husband and wife duo Mr Luke Meier and Ms Lucie Meier, the brand worked with Australian artist Ms Linda Tegg on a grassy landscape of wildflowers inside its HQ. Similarly, shunning the glitzy mise en scène it is usually known for, Hermès presented its pieces against a stone wall maze to highlight the skills and materiality of its collection.

Undoubtedly fashion’s most successful flirtation with design – or craft, more specifically – in recent years has been at Loewe. This year, the Spanish brand has worked with a handful of weavers and textile artists, inviting them to create limited-edition works using its leather. The show was a beautiful showcase of rare craft techniques from little-known talents on the global stage. It goes to show the value in the big fashion brands and their big fashion bucks getting behind craft, design and the skills that make the whole industry unique.