In the mid 19th century, paper made from pulp? (cellulose, wood) was introduced because it was cheaper than cloth-based paper (term?). However, this pulp paper contained acid that causes a sort of slow fires that eventually destroys the paper from within. Libraries today have to consider mass deacidification of their older collections. Books printed 1850--1950 are at risk; more recent books have better paper.
Maintaining a library used to be the privilege of princes, wealthy people, and universities. The growth of a [public library]? system started in the late 19th century and was much helped by donations from Andrew Carnegie.
Throughout the 20th century, libraries have faced an ever increasing rate of publishing, sometimes called an information explosion. The advent of [electronic publishing]? and the Internet means that much new information is not printed in books, but made available online, on CDROM, or in the form of ebook?s (electronic books). This does not necessarily make life easier for libraries, and so far has not resulted in any decline in the rate of paper publishing.
There have also been new developments in the process of publishing books. Technologies such as [print on demand]? have made it easier for less known authors to make their work available to a larger audience.