Open access is when academic research is made freely available for anyone to read and re-use. As with open access journals, there are different business models for funding open-access books, including publication charges, institutional support, library publishing, and consortium models. OECD Publishing uses a freemium model by making its books available online in HTML with the option to purchase a print copy. There is some evidence that making electronic editions of books open access can increase sales of the print edition.
While open access to journal articles has become very common, with 50% of articles published in 2011 available as open access, open access to books has not yet seen as much uptake. However, there are dedicated open-access book publishers such as Open Book Publishers, punctum books, and others who publish both books and journals, such as Open Humanities Press. A report released in 2015 by the UK's main funding body for research, the Higher Education Funding Council for England, states the importance of open access monographs: "Monographs are a vitally important and distinctive vehicle for research communication, and must be sustained in any moves to open access."
The OAPEN (Open Access Publishing in European Networks) online library and publication platform provides access to thousands of peer-reviewed academic books, mainly in the humanities and social sciences. The OAPEN Foundation  also provides a directory of open access works via Directory of Open Access Books (DOAB).
- "Budapest Open Access Initiative". Budapest Open Access Initiative. Retrieved 2015-10-22.
- "Berlin Declaration on Open Access to Knowledge in the Sciences and Humanities". Max Planck Open Access. Retrieved 4 June 2014.
- Ferwerda, Eelco (2014). "Open access monograph business models". Insights. 27. doi:10.1629/2048-7754.46. ISSN 2048-7754.
- Suber, Peter (2012). Open access. MIT Press. p. 107. ISBN 9780262517638. Retrieved 4 June 2014.
- Archambault, Eric; Amyot, Didier; Deschamps, Philippe; Nicol, Aurore; Rebout, Lise; Roberge, Guillaume (August 2013). "Proportion of Open Access Peer-Reviewed Papers at the European and World Levels—2004-2011" (PDF). Retrieved 4 June 2014.
- Collins, Ellen; Milloy, Caren (2012). "A snapshot of attitudes towards open access monograph publishing in the humanities and social sciences – part of the OAPEN-UK project". Insights. 25 (2): 192–197. doi:10.1629/2048-7718.104.22.168.
- Bonn, Maria. "Free exchange of ideas Experimenting with the open access monograph". College & Research Libraries News. Retrieved 10 June 2014.
- "Monographs and open access: A report to HEFCE" (PDF). August 2013. Archived from the original (PDF) on 20 July 2020. Retrieved 21 August 2015.
- "Monographs and open access". August 2013. Archived from the original on 20 July 2020. Retrieved 21 August 2015.
- "Organisation". OAPEN. Retrieved 3 October 2020.
- "Monographs", p. 112 in Martin Paul Eve, Open Access and the Humanities, Cambridge University Press, 2014. full text
- "Open-access monographs", p. 419 in Peggy Johnson, Fundamentals of Collection Development and Management, American Library Association, 2014.