Historically, most of society’s writings and visual images have been recorded on paper.
Lignin contains phenolic entities sensitive to light which develop chromophores or conjugated double bonds in the chemical structure which can absorb light in the visible range. This makes paper containing high amounts of lignin very prone to discoloration or yellowing. While there is no doubt that lignin in paper contributes to its discoloration, there is little evidence to show that paper containing lignin loses strength faster than paper of similar quality without lignin (Luner, 1988). However, standard specifications for durable paper allow no more than 1% lignin, for papers used in archives, libraries, and other permanent records.