Director Paul Thomas Anderson got the initial idea for the film while he was sick in bed one day. His wife, Maya Rudolph, was tending to him and gave him a look that made him realize that she had not looked at him with such tenderness and love in a long time.
In preparation for the film, Daniel Day-Lewis watched archival footage of 1940s and 1950s fashion shows, studied famous designers, consulted with the curator of fashion and textiles at the Victoria and Albert Museum in London, and apprenticed under Marc Happel, head of the costume department at the New York City Ballet. He also learned how to sew, and he practiced on his wife Rebecca Miller, trying to recreate a Balenciaga sheath dress that was inspired by a school uniform.
Vicky Krieps did not meet Daniel Day-Lewis until her first day on set. As Day-Lewis famously stays in character during production of his films, Krieps was instructed to refer to him as "Reynolds" for the duration of filming. In multiple interviews promoting the film, Krieps still referred to Day-Lewis as "Reynolds."
The Spanish fashion designer Cristóbal Balenciaga's relation with his work and the way he led his life, with director Paul Thomas Anderson's words, "monastic life," inspired the character of Reynolds Woodcock.
Paul Thomas Anderson disputed reports that he served as his own cinematographer, stating that while no director of photography was hired, he collaborated with and was advised by his camera operators and gaffers, since he does not have the technical expertise of a cinematographer.
Daniel Day-Lewis and Lesley Manville became real-life friends for six months prior to filming began in order to establish the close relationship between Cyril and Reynolds. Though most of the time they had to text each other back and forth as Manville lived in London and Day-Lewis had two homes between Ireland and New York.
There are 90 minutes of Jonny Greenwood's score used during the 130 minute running time of "Phantom Thread" . Greenwood says he was influenced by the works of Nelson Riddle and Glenn Gould from the 50's.
The character of Rubio Guerrero is based on real life Dominican playboy Porfirio Rubirosa (Ruby). His marriage to the character of Barbara Rose is also based on the short-lived factual marriage between Rubirosa and Woolworth heiress Barbara Hutton.
Although no date is given during the film, the story likely takes place between May 1953 (suggested by the client buying a gala gown for what is most likely a Coronation ball), and October 1954 (A U.K. Vogue magazine from October 1954 appears towards the end of the film). On the other hand, there's evidence in the DVD extras that the time frame extends to at least the end of 1955: In the slideshow of photos taken during the filming, there's a close-up of a menu on a banquet table. At the top is written "Christmas Dinner 1955". Whether this is from a scene kept in or cut from the film can't be known from this one photo, but it's clear that the original intent was for the story to run to at least this date.
The typeface used for the credits is called Reynolds Stone and it was created by the English wood engraver, typographer, and designer Reynolds Stone, who was a close friend of the parents of Daniel Day-Lewis. When Paul Thomas Anderson and Daniel Day-Lewis were devising the character of Reynolds Woodcock, they agreed that they wanted the film to have a sort of "Reynolds Stone look," and the character's name, Reynolds Woodcock, was partly inspired by this as well.
Early in the film, Reynolds tells Cyril, "It's comforting to think the dead are watching over the living. I don't find that spooky at all." This is similar to a wide variety of quotations on the subject, such as the following loosely similar sentiment, from Stanley Kubrick to his daughter Katharina: "It would be nice if there were ghosts, as that would imply that there is something after death."
Krieps' character was originally named "Agnes". For various legal reasons, this proved unsatisfactory. The new name was either suggested by Krieps to Anderson because "Alma" was the name of Alfred Hitchcock's wife Alma Reville (her version) or from Anderson Googling popular birth-names in Luxembourg in the 1930s (his version).
Chosen by the National Board of Review as one of 2017's top ten films. At the 90th Academy Awards, the film won for Costume Design with five other nominations, including Best Picture, Best Director, Best Actor for Day-Lewis, and Supporting Actress for Manville. It also received two Golden Globe nominations: Best Actor - Drama (Day-Lewis) and Best Original Score, as well as four at the 71st British Academy Film Awards, winning for Costume Design.
Director Paul Thomas Anderson, a fan of Jordan Peele's television work, was shooting this film in London during the winter. In a down, miserable period for the director, he went to see Peele's Get Out (2017). Anderson was inspired by the film and said that it had made him feel a connection, although rather ironically, back home to America. Peele had later seen this film, which he really took to. Anderson would later interview Peele about the latter's latest horror film Us (2019) in Fangoria magazine.
The type of mushroom Alma uses to poison Reynolds is most likely a Omphalotus olearius, commonly known as a Jack o'Lantern, often mistaken for chanterelle mushrooms. While not deadly, Jack O'Lanterns do cause severe nausea and diarrhea.