Rihanna has taken time out from celebrating her 25th birthday in Hawaii with Chris Brown to announce her new partnership with MAC Cosmetics.

The Diamond hitmaker revealed the she has inked a lucrative deal with the makeup giant, making her the first artist to be named as a creative partner for the brand.

"That's right baby, I'm a #MACgal now! Get into it, package designed and products created from scratch by yours truly!" she told her 28 million followers on Twitter.

As part of her collaboration, RiRi Hearts MAC, the singer will release four collections of products that will include lipsticks, eyeshadows and brushes.

The first - a signature red lippie based on the brand's famous staple Ruby Woo - will launch later as part of the summer range. RiRi Woo will be sold with all four collections.

Earlier this month, RiRi ventured into fashion by launching her first fashion collection, a collaboration with high street favourite River Island at London Fashion Week.