Repository-based or “Green” open access
“Green” open access is the term used when the author accepted version of a published work is deposited into a subject-based repository or an institutional repository. Every university in Australia has a repository for this purpose. International examples include PubMed Central® (PMC) and Europe PMC. Articles may have a Creative Commons License applied, which specifies how the article can be used
Journal-based or “Gold” Open Access
“Gold” open access refers to publishing in a fully open access scholarly journal, one where the publisher of the journal provides free and immediate online access to the full content of the journal and the final published versions of articles in that journal are fully open access. Articles have a Creative Commons License applied, which specifies how the article can be used. Business models for this form of open access vary. In some cases, the publisher charges an article processing charge (APC), which may be paid by the author’s institution or funding body or by an individual researcher. APCs may also be paid as paid of transformative agreements. A comprehensive list of open access journals is maintained by the Directory of Open Access Journals. There is also a Directory of Open Access Books.
“Diamond” Open access
“Diamond” open access refers to open access journals that are free for readers to access and for authors to publish in. These journals are often community-driven and supported by institutions or by national or regional infrastructure. A recent report commissioned by cOAlition S explored the huge global range of Diamond open access journals.
“Hybrid” open access
“Hybrid” open access refers to when an article processing charge is paid for an individual journal article to be made open access in an otherwise subscription journal. This type of open access always has an APC associated with it and these APCs are usually higher than for fully open access journals . Hybrid open access is not supported by any universities in Australia and New Zealand.
“Bronze” open access
“Bronze” open access refers to a freely available journal article that has no open license (and hence cannot be considered fully open access).
“Black” open access
“Black” open access refers to illegal open access.
Further reading: this article discusses the frequency of all the various types of open access.