discoloration white deposit newton rings bleeding inks dyes odor different feel paper wei t'o caused odor white residues rings cockling yellow discolorations adhesive bleeding ref name porck conservators british library acknowledge existing mass deacidification processes still developing research needs conducted chemical mechanical effects history research process development mass deacidification nbsp along microfilm lamination nbsp developed early mid th century response chemical process hydrolysis fibers constitute paper providing
Applied science Library and museum studies Mass deacidification