The publishing field for religious books in Jewish law or Rabbinics is very active and classic works from the 15-20th century are reprinted frequently in small editions generally without copyright restrictions.
Catalogs of other facsimile and reference book publishers were added with the goal of creating a central portal for Rabbinics and Jewish Studies.
As for Judaica and Hebraica the percentages are even higher due to inferior paper quality, low print runs, and the wilful destruction of Jewish books during the Holocaust.
The Judaica Archival Project continues to scan, save and exchange copies of every rare Sefer that readers can order for study.
This sharing of resources although modest in scope, is more effective than large scale preservation projects, which are difficult to fund in the present economic climate.