Suranne Jones doesn't think she "would've been able to do" "Gentleman Jack" without the show's intimacy director.
The 40-year-old actress plays industrialist Anne Lister in the BBC period drama, but if she hadn't received assistance to help portray the character's intimate scenes with lover Ann Walker, who is played by Sophie Walker, she may have not taken on the part.
She said: "We were introduced to an intimacy director.
"We were very thorough and sensitive. They helped us work on that side of her relationship.
"If we hadn't had all of that, I don't think I would have been able to do the role. I really don't."
Anne was a no-nonsense English landowner who kept diaries chronicling her life in the 19th century, including her lesbian relationships, and a sixth of the documents were written in code.
Suranne threw herself into the role, reading countless books about Anne, and she even explored coal mines and fed pigs in Halifax, west Yorkshire, to get into character.
She said: "You kind of want a job, and then you actually go in and start to work on the scenes, and then you really want the job.
"And then you get scared, and go, "Oh god, just give me this job, please."
"When I got the call to say yes, I said, "Give me everything." I then got about five books sent through, I got a dissertation sent through.
"We went stomping up to the coal mines. We fed some pigs on the way."
Suranne also explored Shibden Hall in west Yorkshire, Anne's ancestral home, where the TV series - which was written by Sally Wainwright - was filmed.
The "Doctor Foster" star added to DIVA magazine: "I got some of Sally's notes sent through. We went on a reccy and walked all the way round Shibden."