Although it seems like a defiance of common sense, by the time vinyl was first used as a material for manufacturing children's toys, dolls had already had a long history of fragility. Vinyl dolls solved that problem. They didn't break easily, as porcelain and bisque dolls did; they didn't manifest crazing or chipping over time as did composition dolls; and they didn't crack or split at the seams, as with hard plastic dolls. Vinyl dolls also made rooted hair possible in dolls, replacing the glued-on wigs of hard plastic and composition dolls.
Of course, early vinyl dolls still had their problems. Hard vinyl tended to lose its color over time -- these days, many vintage vinyl dolls have arms, legs, and torsos that are each a different shade, making them look rather washed out from the neck down. Likewise, soft vinyl sometimes discolored as well, darkening or turning orange or yellow with age.
Vinyl became popular as a material for making dolls at a time when fashion dolls were also becoming very popular. As a result, many vintage fashion dolls are made from vinyl. Although at the time, toddler dolls -- dolls that take the form of a small child, or a toddler -- were being phased out, the few companies that continued to make them began to convert to vinyl dolls, as well. Vinyl was also a good material for baby dolls, as it is flexible and durable enough to withstand the play of small children.
Rooted hair was a huge incentive behind the shift to vinyl dolls. Although saran wigs could be washed, combed, and curled, they were also more likely to lose hair with repeated combing, among other problems. The rooted hair of vinyl dolls was much more appropriate for "beauty shop" play, as it tended to be more durable. As a result, when companies made the shift to vinyl dolls, it was usually first to a hard plastic body with a vinyl head. Such dolls started appearing as early as the early to mid-fifties.
Baby dolls, on the other hand, typically had a hard plastic head and a soft vinyl body; vinyl, a much softer and more pliable material, is more realistic as baby's skin and more huggable for young children. Later baby dolls were made entirely of soft vinyl, some with rooted, baby-like hair. These vinyl dolls sometimes had drink-and-wet devices in them, which enabled them to pass water, bottle-fed to them through a hole in their mouths, through another hole into their diapers. Sometimes vinyl baby dolls also had voice boxes or "criers" in them.
Although today's vinyl dolls are very different than the first ones to appear on the market, many modern dolls and toys are still made from vinyl. Vinyl has proved to be a durable material, not just in its ability to withstand playwear, but also in its ability to answer to the demands of the toy market.