If you're struggling for an original Christmas present - how about a wooden dress?
At a recent state gala, Finland's first lady wore a dress made from the country's birch trees.
But there was nothing frivolous about why she chose the dress - she wore it to support a new technology which could reduce the environmental damage caused by the fashion industry.
The dress worn by Jenni Haukio, a poet and wife of the president, was created by academics at Finland's Aalto University using a new sustainable technology called Ioncell.
The academics say the process is more environmentally-friendly than cotton and synthetic fibres and makes use of wood that would otherwise be wasted.
In eastern Finland's forests, there is a thinning process of removing some trees to make room for others to grow - and these smaller birch trees are now becoming the source for clothing.
Off the peg
This process creates textile fibres from materials like wood, recycled newspaper, cardboard and old cotton textiles, which can be turned into dresses, scarves, jackets and even iPad cases.
Prof Pirjo Kaariainen of Aalto University is pleased with the feedback on the dress.
"It was designed by a young fashion and design student here at Aalto who wanted to give respect to Finnish nature and to the country's tradition of strong women."
Prof Kaariainen says the fibre works well for clothing because it is "soft to touch, it has a lovely sheen and falls beautifully".
There are growing calls for the fashion industry to urgently reduce its damaging effects on the environment.
The industry causes 10% of global carbon emissions and uses nearly 70 million barrels of oil each year to make polyester fibres, which can take more than 200 years to decompose.
Plastic microfibres from synthetic clothing are part of the problem of human-made materials that wash up along ocean shores.
Campaigners are calling for consumers to buy new clothes less often, but changing consumer behaviour is difficult when fashion companies promote new lines every season.
Making clothes from sustainable materials could be a more realistic alternative.
Although Ioncell was developed by chemists and engineers at Aalto and Helsinki universities, Prof Kaariainen says it was important that the dress was made by designers so that people would want to wear it.
"People want garments that look good and make them feel good, so there is no choice but for the design to be good," she says.
"We need to make a systemic change where sustainable materials are embedded in the system and people can easily buy beautiful and comfortable garments which don't cause environmental problems."
Finland's first lady is not the first famous wearer of Ioncell - France's President Macron wore a scarf made from recycled blue jeans when he visited Aalto in August.
Ana Portela, a fashion designer who promotes sustainable fabrics says consumers will be persuaded to try sustainable fashion if it is worn by influential people.
"This dress is not a high street design but it definitely fulfilled its purpose and it is important that people like the first lady advocate for more sustainable options and push new innovations," she says.
She says consumers must "lead the revolution" by using their purchasing power to incentivise companies to produce sustainable clothing lines.
"We need to take a different approach to our understanding of what is fashion," she says.
"This could be buying second hand-products, products with a certified origin, using more efficient natural fibres like hemp, buying a filter bag for your washing machine to stop microfibres entering the water system or pressuring companies to do better."
The Aalto team aim to have a pilot production line for the new fibre by 2020 and hope that such clothing, made from recycled birch trees, will be available to buy for Christmas shopping lists in 2025.