paper-backup
With HCCB (High Capacity Color Barcode) of which an implementation is Microsoft Tag you can get 1.5 MB with 600dpi color on a A4. If you add the best compression techniques (ppmd) depending on the source material you could get 8 times as much english text, easily fitting the pearls or religion: Tenach, New Testament, Quran, Mahabarata, The Dhamapada, the Atthakavagga and the Parayanavagga, Rhinoceros and Lotus Sutra, The Book of the Dead and the Sri Guru Granth Sahib and explanatory texts and commentary on one single A4....