Diamond OA (also called platinum OA) journals charge neither subscription fees nor article-processing charges. They are usually run by academic communities, learned societies, university presses or library publishing services. The 2021 OA Diamond Journals Study (Bosman, Frantsvåg, Kramer, Langlais, Proudman) identified roughly 29,000 such journals worldwide, predominantly in the humanities, social sciences and Global South publishing ecosystems (notably AmeliCA, Latindex, Redalyc, SciELO). Diamond OA aligns most directly with knowledge-equity goals because it removes both reader and author paywalls.
References
- Bosman J et al. 'The OA Diamond Journals Study', Science Europe / cOAlition S, 2021. Action Plan for Diamond Open Access (2022).