Name: Brenda
Message: How would you suggest to dye a My Size Barbie doll's hair?

I wouldn't. The heat required for dyeing might ruin the hair, making it uncombable, and dye or boiling water on the doll's face might damage it permanently. Also note that dye can be used only to darken a fiber, never lighten it, as dye is transparent; this means that your blond Barbie could become a redhead (or a greenhead), but a dark-haired doll cannot.

I do not know what your My Size Barbie doll's hair is made of; the two most likely possibilities are nylon or polyester. You MUST know the fiber content of your doll's hair (or anything else) before you attempt to dye it, as otherwise you may choose the wrong type of dye and have a total failure. Polyester is the more difficult of these two fibers to dye. To be dyed at home, polyester must be boiled for an hour with a special type of dye called 'disperse dye' plus a noxious-smelling carrier chemical. See "Dyeing Polyester with Disperse Dyes".

Nylon is easier to dye than polyester; it requires scalding hot water (cooler than boiling temperature), an acid such as vinegar, and a type of dye called 'acid dye', such as that found as part of the mixture in all-purpose dye. It might be possible to hold your doll so that the hair is submerged in the hot dyebath, without melting the doll or dyeing her face, but I would not recommend that you attempt this if a failure would be a great problem for you. All-purpose dye is sometimes used to color doll's vinyl faces during restoration, so dye spills could be quite unfortunate.

It seems to me that it would be far more practical to buy or make a wig for your doll. A variety of wigs for My Size Barbie dolls are being sold on Ebay.