RB: What was your inspiration for Bella's look in the film?
RM: We had to keep Bella's makeup natural but still make her stand out among all the other mythical creatures with their dramatic makeup. I've often described her look as "flawed yet flawless." She is a modern-day fairy-tale character, a heroine beloved by so many. Her look needed to be comparable to the flawlessness of a Snow White or Sleeping Beauty. Yes, she is a real human girl, and that is where the flawed part comes in, but if her look was too plain she wouldn't be able to hold her own next to these creatures, and the movie would be a little off-kilter.
RB: What are your tricks to getting a natural look like Bella's?
RM: I'd say the key to Bella's look is flawless skin, naturally enhanced eyes, pretty peachy-pink cheeks, and matching lips. Since Bella is naturally pale, the secret to keeping her from looking washed out is to warm it up a bit with the blush and the lips. Also, stay away from cool tones and use warmer ones instead. I used a combination of five different blushes to get Bella's look in the film. (Note: Mathews is keeping specific products on the hush since the series isn't over yet.)
RB: Do you have a favorite look for Bella in the films?
RM: I love how Bella looks in both New Moon and Eclipse. Kristen is such a naturally beautiful girl, but when we finish the Bella makeup and put the contacts in she looks completely different — it's astonishing. Chris Weitz (director of New Moon) said that it looked like Kristen as Bella had stepped out of a classic Renaissance painting, and I agree. We also had a lot of fun creating Bella's vampire look for New Moon. You only see a flash of it in the movie, but it was setting the design for what Bella will become in Breaking Dawn. Bella becomes the most badass vampire of them all, and I had a blast being able to depict on-screen what she would look like in the minds of the readers.
RB: What's your one superhero product you can't live without on or off set?
RM: I only get one?! That would have to be Clé de Peau Beauté Concealers.
Source