Stella McCartney got the chance to re-evaluate her career during the Covid-19 lockdown.

The 49-year-old retreated to her farm in Wiltshire, England, with husband Alasdhair Willis and their four children when the virus outbreak began and restrictions were put in place across the country to help prevent the spread of coronavirus.

However, Stella confessed that she struggled to stop working at first, and eventually had a moment of clarity that made her stop and think about what she was doing with her decades-long career.

“I was afforded time to pause and re-evaluate why I do what I do, and why it’s important,” she told British Vogue. “And the answer was, I have this mission that I’m on. I’ve never just done fashion. What I create has always had to have a meaning and a value system."

The designer said she wrote a "personal manifesto" and overhauled her working life and approach to sustainable fashion.

"I wanted to reduce what I produce. This idea of reduction is more sustainable and feels much more precious, human and right. I’ve been wanting to have a new set of codes of language around sustainability. I wanted to work on what words are important to me and then put them into clothes," Stella continued.

Her spring/summer 21 collection is made up of 26 pieces, and represents each letter of the alphabet, with every garment being made from leftover stock.

“I don’t like how we always have to change things up so quick,” Stella said of the "real and honest" collection. "Because of lockdown, we couldn’t get any fabrics anyway. So my idea of using existing things became a necessity.”