Publishing under open access conditions also costs money: infrastructure, personnel, and other services must be financed. There are various business and financing models for this, such as Diamond Open Access. In contrast to the Gold Open Access model, Diamond Open Access involves direct financing of publishing (e.g., by institutions or consortia), meaning that no fees are charged to readers or authors.

In addition to the business aspects, the Diamond Open Access model supports science policy demands for fair access, organizational sustainability, and digital sovereignty. In this respect, Diamond Open Access models contribute to the diversity of the publishing landscape and the dissemination of scholar-led infrastructures.

Definitions of Diamond Open Access

There are different definitions of Diamond Open Access. What they all have in common is that no fees are charged to readers or authors. In September 2025, the DFG-funded “Service Centre Diamond Open Access” (SeDOA) published a minimal definition for journals and books that attempts to combine different national and international perspectives:

In Diamond Open Access journals, quality-assured articles are published free of charge for authors and readers under an open access-compliant license. The journal or title rights belong to the scientific community. Diamond Open Access journals serve scientific communication and non-commercial purposes.

In Diamond Open Access books, quality-checked content is published free of charge for authors and readers under an open access-compliant license. The book and series titles belong to the scientific community. Diamond Open Access books serve scientific communication and non-commercial purposes.

These two definitions initially refer to the quality assessment of content and the associated standards of scientific work. Subsequently, the aforementioned freedom from costs and fees is emphasized, thus ensuring fair access for all researchers. After all, it is stated later that the corresponding journals, book titles, and series titles belong to the researchers or the scientific community as a whole. The definitions also emphasize the need for an open-access-compliant license, i.e., one that is as open as possible, as well as the fundamentally non-commercial nature of publications in the diamond open access model. Since both aspects are the subject of intense debate, we would like to explore them in more detail.

Issues of non-commerciality

A key starting point for the entire open access movement since the 1990s has been criticism of the increasing commodification of scientific knowledge in the form of scientific publications. Regardless of the development of other open access models and projects aimed at accelerating the transformation, diamond open access models in particular formulate the fundamental claim that scientific publications serve primarily the purpose of communication, not monetization. In its most extreme form, this is understood as a demand for non-commerciality, which only allows for the involvement of non-profit actors in the process of scientific publishing.

At the same time, many active publishing contexts (e.g., university presses) show that the involvement of commercial, profit-oriented actors is useful or even necessary. Depending on the case, services in the areas of translation, editing, layout, typesetting, print-on-demand, marketing, and distribution can be provided more cost-effectively and in a more needs-oriented manner by these actors. The fundamentally non-commercial purpose of diamond open access models remains unaffected by this.

“True” open access licenses

The Berlin Declaration on Open Access to Knowledge in the Sciences and Humanities (2023) proclaims that open access publications should be digitally accessible, free of charge, and publicly available via the Internet, and that they should be readable, copyable, distributable, printable, and searchable without technical or legal barriers. Such open access-compliant reuse is only possible with a very open license. Of the widely used Creative Commons licenses, only CC BY and CC BY-SA meet these requirements.

At the same time, more restrictive Creative Commons license forms can be useful under certain conditions, for example, if commercial reuse (CC BY-NC) for the reproduction of works of art or modifying reuse (CC BY-ND) for medical guidelines is to be restricted. Even if such individual decisions are understandable in certain contexts, they are not in line with the requirement for openness formulated in the Berlin Declaration. In this sense, they are not open access-compliant and should remain the exception for diamond open access publications.

Commitment from BerlinU

BerlinUP is a scientific, non-commercial open access publisher that does not charge authors any fees—the publisher is committed to the diamond open access model. BerlinUP thus deliberately sets itself apart from profit-oriented, commercial publishers. The publisher thus follows the demands of scientific organizations and funding agencies to enable freely accessible first publications with science-related publication infrastructures from public institutions.

Accordingly, BerlinUP is involved in various organizations and projects at the national and international level. As a member of the AG Universitätsverlage (University Publishers Working Group), the publisher networks within the German-speaking world and collaborates on standards for high-quality and sustainable publishing. In the national Service Centre Diamond Open Access (SeDOA), the publisher contributes its practical expertise in the areas of publication services, community building, and innovation development across all locations. Finally, individual supporting institutions of BerlinUP provide financial support to international Diamond Open Access infrastructures in order to promote the transformation to fair open access.