Benzoyl Peroxide

Benzoyl peroxide, also known by the trade name Oxy, is an organic peroxide commonly used for treating acne. Among collectors and the American Girl fan community, it is commonly used for removing ink and dye stains on dolls. As with most peroxides, benzoyl peroxide acts as a bleaching agent, causing colour degradation on certain fabrics.

Use on dolls
As mentioned earlier, benzoyl acts as a bleaching agent, fading out any dyes that come in contact with the substance. This property has been put into good use by collectors, as most other substances are of little to no effect with stains. The vinyl used in dolls is a soft, porous material, which, while it allows for easier repair and servicing, it also makes the dolls' plastic parts susceptible to staining, as ink can seep through and sit in the plastic - this also explains why American Girl uses colorfast dyes in their doll clothing, and why certain articles, especially third-party ones from Our Generation and the like, may leave out unwanted ink marks.

Benzoyl can be bought over-the-counter at pharmacies, and usually comes in 2.5, 5 and 10-percent concentrations in gel or cream form. They're typically applied on the affected area, along with some exposure to the sun or a warm lamp which speeds up the process. Depending on the stain it can take several hours to even weeks or months for the stain to fade away. Caution should be taken, however, especially when applying the cream near painted areas like face paint, or clothing.