The pressure to create authentic hair and make-up design on the new season of The Crown felt higher than ever, one of the show’s creative leads has told HuffPost UK.

Season 4 of the Netflix series dramatises fictitious accounts between the royals set in the years between 1979 until 1990 and introduces two of the century’s most iconic females, Princess Diana (played by Emma Corrin) and former British prime minister Margaret Thatcher (played by Gillian Anderson).

Reviews have been favourable, and key moments in the early episodes include a hilarious scene in which Margaret Thatcher plays Ibble Dibble with the royal family, before heading out on a shooting trip with the Queen at Balmoral, dressed in one of her iconic blue two-piece suits.

Cate Hall, the hair and make-up design lead on the show, revealed how the stakes have never felt higher as the show approaches more modern times. “Of course, the more familiar a period is to the audience, the greater the pressure to get it right,” she says.

“Everyone engaged in the show is so committed to realising a world which is believable, that the pressure motivates us to try harder to do justice to the audience’s memory,” adds Cate. “I used loads of my family photo albums for reference which was particularly useful.

“We’re trying to mostly replicate ‘normal’, every-day rather than high fashion looks. The dangerous element comes from feeling like you know it, when of course memory is fallible, so you still need to research everything thoroughly in order to achieve the kind of precision The Crown is known for.”

Cate says that nostalgia has a “wonderful, but possibly dangerous effect” because of how subjective it is.

“During prep as we were developing the look for Thatcher at the start of the series, [writer] Peter Morgan gave us a useful note reminding us not to let our memories and feelings about her interfere with the process as despite what she became know for, when we establish the character she is full of promise and passion” Cate explains.

“I had to leave my own judgement at the door. I was grateful to recognise that so early on.”

When it comes to recreating the familiar looks of Diana and Thatcher and the cohort of royals, Cate says “the truth seems to lie somewhere between accuracy and believability.”

“If we do something distracting in trying to replicate a real character, then we take the viewer out of the show, so that’s a real no,” she adds.

For Diana, Cate aimed to tell the story of her growth and development, from relatively ordinary girl living in Earl’s Court with friends to being on the front of every newspaper and magazine – as well as representing the potential changes in her state of mind, which comes with that.

“The extent to which her look became deliberate and manufactured for the media is a key for our visual journey,” Cate explains. “She transforms in season 4 from a natural looking teenager to a media-savvy icon who uses hair and make-up styling as a suit of armour.”

As for Margaret Thatcher, Cate isn’t lining up to praise her sartorial choices.

“I know people call her a fashion icon but I can’t see it from a hair and make-up point of view,” she says.

“Her hair is a kind of 80s re-hash of a classic 1960s roller set and brush out. She was definitely iconic from a stateswoman perspective with a very precise and consistent visual brand, but I think her look was recognisable rather than leading.”

Once the looks were finalised, it was Cate’s job to work out how to achieve them logistically, and the main factor to bear in mind was how advancements in technology in the era meant styles changed dramatically.

“From my view, the 1980s are a real gift,” reveals Cate. “It was the first period in a few centuries where women were emphasising every feature of the face simultaneously.”

It was the era in which make-up became accessible – but it lacked the sophisticated chemical technology which today allows for the naturalistic looks Cate describes as “smooth, shiny and easily blendable.”

Hence, Diana’s patchier blusher in scenes set in the early 1980s when she was self-styling at home before she moved into the palace.

In terms of hair, the Eighties were the era in which perming and highlighting became en vogue. “This gave us a great palette of texture to play with as well as colour. We had great creative license to move the show into a new era with a look you could almost feel as well as see.”

As the shoot approached, and the focus turned to applying the look on an actor, more was definitely more.

“Typically we start with all the artifice at our disposal; false teeth, wigs, contact lenses, and gradually strip it away until what is left is believable,” says Cate.

She says the key is finding a balance between literal recreation and allowing the actor to embody the person in their performance.

“Typically I find that if we get the silhouette precisely correct then the outline is all the viewer really needs: the actor does the rest with their performance and hopefully we leave enough space that the viewer’s mind fills in the gaps,” she explains. 

With Margaret Thatcher, one sacrifice made in terms of recreating her look was her teeth.

“Margaret Thatcher had some serious dental work throughout the 1980s, but when we tried a series of prosthetic teeth appliances and they seriously compromised [Gillian Anderson’s] performance, it was clear we didn’t need to tell the teeth story to tell Thatcher’s story,” says Cate.

Cate was more hands-on with Thatcher’s wig though, which was aged by removing hair and making what remained more grey for her final episode. “If you can infer strength with a hair-do, we tried,” says Cate.

Creating these two entirely different world famous looks – one polarising, one the subject of the nation’s adoration – awarded Cate more than just another line on her CV: she was constantly taken away from the immediacy of her work and reminded about how both women shaped her own life.

“I was a child in a single parent family in the 1980s so the politics feels acutely relevant to me,” remembers Cate. “It felt really familiar to me and there was a definite sense of comfort in recreating the looks from my childhood.”

The Crown season 4 is streaming now on Netflix.