There are many types of open access journals, and they fall into different publishing models:
- Gold—the publisher makes articles fully accessible on the journal website under a Creative Commons or similar license. An APC is usually paid by the author (or other funder).
- Hybrid – a subscription journal where the publisher allows authors to pay to make individual articles open access. Differs from a Gold OA journal because a library (or other subscriber) is still paying for a subscription to the journal, so the publisher is effectively paid twice for the article, once via subscription, and once via the APC to make the article OA.
- Diamond/Platinum - journals that publish OA but do not charge APCs. Institutions, advertising, philanthropy, etc, fund these.
- Bronze journals—those that are free to read online but do not have a license—are not generally available for reuse.
- Green – refers to self-archiving generally of the pre- or post-print of articles in repositories.
Though green open access generally refers to the post-print of an article, three basic version types are described in archiving policies:
- Pre-Prints – The author's copy of the article before it’s been reviewed by the publisher, or pre-reviewed
- Post-Prints – The author's copy of the article after it has been reviewed and corrected, but before the publisher has formatted it for publication, or post-reviewed.
- Publisher’s Version – The version that is formatted and appears in print or online.
If authors have signed a Copyright Transfer Agreement (CTA), the publisher's policy will determine which version of an article can be archived in a repository. Most publishers allow some green open access. Authors can check their CTA for this information. JISC Open policy finder is a database of publisher copyright policies and self-archiving information that authors can use to check which version they may be allowed to archive. Not all journals are in the Open Policy Finder, so authors may need to check the publisher's website.
