Just what constitutes an Academy Award nomination in the hair and makeup categories is a strange alchemy — nominees can be both department heads and individuals; prosthetics and mechanical devices count just as much as old-school color, light and shading. And all three styles ended up represented in this year’s selection of films: “Victoria & Abdul,” “Darkest Hour” and “Wonder.”

For “Victoria and Abdul,” hair and makeup artist Daniel Phillips and co-hair designer Loulia Sheppard traveled a traditional route, in showing how elderly Queen Victoria’s friendship with servant Abdul Karim helped put color — literally — back in her life. They first emphasized facial creases and eye folds; Victoria’s long life was meant to seem monochromatic and heavy. Even her wig was a cold, washed-out gray. But as her personality warmed, her wig took on a softer tone, and gentle color was introduced again as she visually and emotionally warmed up. Meanwhile, key actors’ beards were created or enhanced with a daily layered-on technique — virtually a requirement for 4K images.

“Darkest Hour” took a man who didn’t much resemble Winston Churchill — Gary Oldman — and transformed him with a full body suit, facial and neck prosthetics, all topped off by careful makeup application for those extended, extreme close-ups. Kazuhiro Tsuji was the only one Oldman would work with to create the transformation; David Malinowsky supervised the prosthetics while Lucy Sibbick served as prosthetic hair and makeup artist.

They worked like three sculptors. The facial prosthetics and makeup had to be both smooth and mobile: Churchill was a man in motion, with expressive facial gestures, glasses that sometimes needed to be torn from his face — and there could not be a seam visible. Meanwhile, he wore a wig made of baby hair, but the piece was so fragile it had to be remade every 10 days.

Special makeup designer Arjen Tuiten was the only one to be nominated from “Wonder,” but it’s easy to see why: During the 40-day shoot he also had to transform a 9-year-old boy (Jacob Tremblay) who had to reasonably look as if he had a rare facial disease — without letting his strings show.

Tuiten created a complete silicone cover for Tremblay’s head and neck, installed prosthetic teeth to make them crooked, and rigged a wire system on his eyes to be able to make them droop (or rise) as needed. The contraption was hidden under his wig, and was so seamless that he’d received comments from doctors experienced with the condition who thought the actor actually did have the condition. But he also had a different challenge in that “Wonder” is not a movie of atmosphere and shadow — Tremblay’s Auggie had to seem real alongside non-afflicted children, in full clear daylight while still appearing to wear no makeup at all.

All of which emphasizes the truth of all of these nominees’ art: If any of what they do calls attention to itself, they have not succeeded in their ambitions. At the same time, there’s clearly more going on under the skin, the hair and the powder than any average viewer can possibly take in.