Variations in eye color, hair color and style, and skin tone result in several different unique dolls in the 18" dolls. There are eight different molds, only six of which are currently in use. The first mold used is referred to as the Classic Mold, and subsequent molds are generally referred to by the first doll to use the mold. 
American Girl does not give a racial designation to any of the face molds and generally, any mold could theoretically be available with any skin, hair, and eye combination. However, the faces do generally map to the general likenesses of perceived racial groups.
List of Face Molds
Eight face molds have been used by American Girl altogether for the 18" dolls:
- Classic Mold: Released in 1986; first used for Kirsten, Samantha, and Molly.
- Addy Mold: Released in 1993; first used for Addy.
- Asian Mold: Released in 1995 and retired in 2011; was only used for JLY 4.
- Josefina Mold: Released in 1997; first used for Josefina
- Kaya Mold: Released in 2002; has only been used for Kaya.
- Jess Mold: Released in 2006; first used for Jess.
- Sonali Mold: Released in 2009; first used for Sonali.
- Marie-Grace Mold: Released in 2011 and retired in 2014; was only used for Marie-Grace.
The Bitty Baby Dolls originally appeared to have four face (and head) molds; originally the Brown, Blond, and Red haired Bitty Babies shared face molds. Because the hair is molded to the head instead of wigged--and thus an integral part of the doll's look--a new Bitty Baby cannot be added to the line as easily, though they can be tinted for hair color. All face molds were slightly changed with the 2013 rebranding, but no new face molds were added.
The Bitty Twins appear to have only a few face molds, based on an open mouth and a closed mouth variation. The faces are slightly different for the "Asian", "Latino", and "African" Bitty Twins. Since the dolls are wigged, variations are easier than with Bitty Babies.
The Wellie Wishers have three face molds so far:
- "Emerson" (used for Emerson)
- "Kendall" (used for Kendall and Ashlyn)
- "Willa" (used for Willa and Camille)
- ↑ The exception is the Asian Mold, as it refers to the perceived ethnic origin of the doll.