How did Captain America wear it when he was thin?

Computer special effects instead of head.

Chris Evans's muscles are all real, without any special effects, but in the first third of the film, the role he wants to play is a small man of 140 kg, which is obviously impossible with traditional makeup. Previously, the team wanted to use some special shooting techniques used in The Lord of the Rings (such as looking up and covering key parts with some props and environment), but there were too many shots involved in these aspects in the film, which could not be done. Lola finally decided to replace her head with digital means, just like The Curious Case of Benjamin Button.

The film crew first found two characters of different sizes, one thin and the other strong, took some actions of standing, sitting and walking, and then handed them over to some special effects companies for testing.

All the plays have to be filmed twice. After Chris finishes each performance, the imitator will perfectly imitate all his actions again, so other actors and photographers should try to repeat them as much as possible. In addition, the makeup artist made his face look like Chris, and then synthesized it by computer.