Saran (PVDC) is also used for high-quality doll hair that is valued by collectors for its shine and softness. However, because PVdC has a high specific gravity because of its high chlorine content, saran doll hair offers poor curl retention.hen formed into a thin plastic film, the principal advantage of Saran, when compared to other plastics, is its very low permeability to water vapor, flavor and aroma molecules, and oxygen.