Although both are manufactured items, Islam has permitted us to do Sajdah on paper, as well as pure sand, natural stone or wood, leaf but not on glass. We have a “nass” (clear verdict) regarding paper’s permissibility from Ahlul Bayt (a.s.), narrated from Holy Prophet (s.a.w.a.). One reason could be that paper to a large extent, retains the nature of its origin that is wood and leaves. Metals like silver, gold, copper etc. are also not permissible for sajdah.   _{Your Comment}