The present invention is directed to a barrier layer which has the ability to substantially prevent the diffusion of stains, such as plasticizers and dyes or other chemicals, onto a surface of a surface covering, from a surface or object in which the surface covering is placed upon. The barrier layer...http://www.google.ca/patents/US5891294?utm_source=gb-gplus-sharePatent US5891294 - Stain blocking barrier layer
