Method for chemical embossing a foamable thermoplastic resin sheet using an ink composition containing a chemical blowing agent

A process for embossing a thermoplastic polymeric material by selective expansion which comprises

• forming into sheet form an expandable mix containing a thermoplastic polymeric material and a chemical blowing agent,
• applying to selected areas of the surface of said sheet an activator ink composition in the form of a plastisol or organosol containing a vinyl resin, 10-200 parts by weight of a plasticizer for said vinyl resin per 100 parts of said vinyl resin, a chemical blowing agent, and a kicker for said chemical blowing agent in said expandable mix and in said activator ink composition, and
• heating said sheet to a temperature and for a time such that in those areas of said sheet in contact with said kicker-containing activator ink composition, said chemical blowing agent in said sheet is decomposed to a greater degree than in the remaining areas and said sheet is thereby differentially selectively expanded.