Justin Bieber has been "pushing men's fashion", his stylist Karla Welch has claimed.
Welch says the 22-year-old pop superstar has paved the way in the industry by taking risks with his signature drop-crotch trousers and long-lined T-shirts, inspired by "stoner" boys, which people are now beginning to copy.
Speaking to Billboard magazine, the 'Sorry' singer's long-term stylist - who first partnered Bieber on his 'Believe Tour' in 2012 - said: "He's been pushing men's fashion for the last five years. If you look at the beginning of the 'Believe Tour', he was getting heat for the drop-crotch pants and super long T-shirts. But now, if you go to any menswear store, you see those styles reflected.
"His approach to fashion has evolved the way his music has evolved. The approach is more chill, but he does take super fun risks."
Welch teamed up with designer Jerry Lorenzo to create five distinct stage looks for Bieber's 'Purpose Tour' - which began in Seattle on Wednesday (09.03.16).
All the garments have modifications such as zippers and reinforcements on the seams for speedy costume changes between songs and Bieber is very pleased with his outfits.
She shared: "We have been buying [Jerry's] stuff for the last two years; it's been a very fun process working together."
However, the fashionista - who has dressed Olivia Wilde and Amy Poehler for red carpet events - revealed her inspiration for the heartthrob's style stemmed from the Seattle grunge period in the early-90s which spawned bands such as Nirvana and Pearl Jam.
She said: "It's more street grunge with a very vintage skater feel.
"I was living in Vancouver (Canada) during the grunge era - I used to go down to Seattle to watch Pearl Jam play - and I always loved how those stoner boys looked. That's what we started doing with the 'Purpose' videos and now with the tour. It's very undone."