"I am literally going to apply this fake tan all over my bikini top," Jemma Violet says, as she smears chocolate brown mousse over her chest, neck and halter-neck bikini.

I'm watching a TikTok video in which the beauty influencer is explaining how to develop a vibrant set of tan lines - without sunbathing.

"Make sure you do your arms and everything... and then wait a couple of hours before washing it off."

A flash frame later and Jemma is showing off two very visible white stripes connected to two white triangles poking out of the top of her boob tube. Tan lines glowing, job done.

Back in the 90s, I remember the abject horror of having tan lines on display and doing all I could to even mine out - with limited success. Fast forward to the mid 2020s and tan lines have become a fashion statement to be shown off.

"When they were out of style they were seen as an imperfection, now they're associated with the summer and an active lifestyle - they've become desirable," Jemma says.

"This year it's risen to a whole other level - they're even on the catwalk."

Some fake tanners are even using masking tape - the type I use on my skirting boards - to create that crisp line across their skin.

"My videos are about getting that tan line safely," Jemma says. "I feel pretty captivating, the look is eye-catching - especially the contrast between the darker skin and the white tan lines."

Jemma is one of thousands extolling the virtues of tan lines, with posts notching up more than 200m views on TikTok.

But alongside fake tanners like Jemma, there are just as many heading outdoors and under the hot sun, determined to create real tan lines - even if that means burning themselves and suffering the painful consequences.

Hashtags such as #sunburntanlines, #sunpoisoning and........

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