Even We Have to Admit Gillian Anderson Pulls Off Margaret Thatcher's Famous Bouffant

Thatcher's political achievements were unprecedented, and apparently, so was her specific hair colour. "It took a lot of work to achieve the right colour and texture hair for Thatcher," Hall said, adding that she prepared for months ahead of production, collecting photo research for each character. Still, it wasn't until she completed a book of images for Anderson's character that she realised the colour would specifically be a challenge. "It became clear that [Thatcher] dyed her hair constantly and, consequently, it changed colour as it faded," Hall said. "I didn't want to dye her wig to achieve that false golden tone, as I knew it would read badly and be unreliable on camera. So, the wigmakers used a huge selection of colours in the wig and we revisited it after camera testing several times to add more highlights."

According to Hall, because Anderson needed so many colour changes, her character required at least three different wigs throughout the season: "We [started] with an iconic golden 'brand Thatcher' wig for episodes one through five, a deeper red tone for episode eight and, finally, a flatter, extra highlighted and thinned wig for episode 10."

While the colour changed regularly, the prime minister's voluminous bouffant shape never wavered. Not one strand of hair was ever out of place, that's for sure. "[Makeup artist] Stacey Holman experimented for weeks to find a method which would achieve the bouffant that Thatcher was so well known for," Hall said, recalling that they finally settled on an extensive process of dry baking and back combing, essentially destroying the hair structure in the wig.

Unlike Meryl Streep in The Iron Lady, Anderson apparently did not wear any prosthetics to resemble Thatcher. Hall noted that, typically, her team focuses on re-creating recognisable hair and makeup styles but let the actors do the rest in their performance.

"We use makeup subtly, but tend not to use prosthetics or teeth appliances unless we feel they are subtle enough not to be noticed," Hall said. And Thatcher's makeup was certainly simple; Hall and her team barely used any base makeup at all on Anderson and none at all during her final, older years, specifically in episode 10.