Karen Gillan spends four hours getting into costume for her 'Guardians of the Galaxy' character.

The 30-year-old actress portrays the assassin alien named Nebula in the fantasy franchise, and she is set to reprise her role in the highly-anticipated 'Avengers: Infinity War' movie, which is slated for release next year.

But the star has revealed it is a painstakingly long process preparing for the movies as she sits in hair and make-up to get blue skin ''stuck'' to her face for numerous hours each day.

Speaking on ITV's 'This Morning' on Friday (08.12.17), Gillan said: ''I've been in there [Marvel Cinematic Universe] for a little while now, nearly five years playing this blue bald character.

''It takes four hours in the morning of having a skin stuck on my face.''

'Avengers: Infinity War' will see the hero squad, which includes Iron Man (Robert Downey Jr.), Captain America (Chris Evans), Thor (Chris Hemsworth), The Hulk (Mark Ruffalo), Scarlet Witch (Elizabeth Olsen), Vision (Paul Bettany), Black Widow (Scarlett Johansson) and Hawkeye (Jeremy Renner), join forces with the 'Guardians of the Galaxy' troop to save the Earth.

The two teams will have to work together to fight intergalactic tyrant Thanos, but they will also receive a helping hand from Spider-Man (Tom Holland), Black Panther (Chadwick Boseman), Dr Strange (Benedict Cumberbatch), as well as Captain Marvel (Brie Larson), which will mark the 28-year-old star's debut in a Marvel production.

And Gillan has teased the forthcoming movie is going to be ''the most epic, cinematic event of all time''.

Speaking previously to BANG Showbiz, she said: ''It's amazing. It's going to be the most epic, cinematic event of all time.''

Gillan has had a busy year as she has not only been shooting 'Avengers: Infinity War', she has also been filming 'Jumanji: Welcome to the Jungle', which sees her portray Ruby Roundhouse.

And though Gillan underwent gruelling fitness sessions in preparation for the follow up to the 1995 original movie, which starred the late Robin Williams, she fears she has taken her foot off the pedal and Nebula may be a ''little less in shape'' than in the previous two instalments.

She said: ''When I was shooting this I was just training every second that I had.

''I was doing a lot of fight choreography and dance lessons basically so it was actually really intense but I've calmed down a little bit. Nebula might be a little less in shape these days.''