To help Ryan Gosling stay in character, the real doll was treated like an actual person, as is done by the characters in the movie. She was dressed privately in her own trailer and was only present for scenes that she was in.
The "Real Doll" was featured on The Graham Norton Effect (2004). The doll was given to the show and was stated as costing $6,000. She arrived in the same kind of crate that is shown in the movie. To test how real the doll looked, they sat her in a bar with drink in hand, sunglasses, and a speaker placed on her so they could talk to whomever came up to talk to the doll. One man was told to go into the bathroom, take off his pants, and wait for her, and he did just so.
The trivia item below may give away important plot points.
The real doll had nine different faces, which were used to show a sort of evolution of the character. The doll starts with a face with heavy make-up, but then later uses a more natural looking face without make-up. Finally, the doll's face becomes slightly green to reflect her "failing health."