An exhibition of artwork produced by tennis star Martina Navratilova hitting tennis balls dipped in paint has opened in Paris.
Navratilova, 50, has been working on the project in secret for four years with Slovak artist Juraj Kralik.
"What I like is that you hit the ball but you don't exactly know what you're doing," she told the AFP news agency.
More than 60 canvases have been created for the Art Grand Slam show at Roland-Garros, home of the French Open.
Kralik came up with the project in Navratilova's Czech home town, where she first learnt how to play the game.
He first put the idea to Navratilova in 2000. Between 2001 and 2005, the pair created the works on the courts of the four Grand Slam tennis tournaments in New York, Melbourne, Paris and Wimbledon.
The tennis balls were covered in paint and hit onto a canvas that was hung on a wall or laid out on the ground at each of the four Grand Slam venues.
Navratilova told AFP that she used her forehand for most of the shots.
The exhibition is in Paris until 20 August
She said her favourite canvas is titled Way of My Life, featuring two loops that spiral upwards to the edge of the painting.
"It represents my career, with a small loop and a big loop and at the end it shows I'm finished," she said.
Navratilova won nine Wimbledon singles titles and a total of 18 Grand Slam singles titles during her career.
She retired after winning the mixed doubles title at the US Open with Bob Bryan last year.
The exhibition, which also includes a documentary about Navratilova, runs until 20 August.