Understanding Open Access Models: Gold, Green, and Diamond

Open access publishing has transformed how research reaches readers, but the term "open access" covers several distinct models with different implications for publishers, authors, and institutions. Understanding these models helps journal publishers choose approaches that align with their missions, financial realities, and community expectations.

The Core Principle: Removing Access Barriers #

At its heart, open access means readers can access research without paying subscription fees or per-article charges. The Budapest Open Access Initiative (2002) established this definition, envisioning a world where scholarly literature is freely available to anyone with internet access.

But "free to read" doesn't mean "free to produce." Academic publishing involves real costs—peer review management, editorial work, copyediting, platform hosting, metadata registration, and long-term preservation. Different open access models address these costs differently, creating the landscape we navigate today.

Gold Open Access #

Gold open access refers to immediate, free availability of published articles on the journal's website. The "gold" designation doesn't specify how costs are covered—only that final published versions are freely accessible from publication day.

APC-Based Gold Open Access #

The most common gold model involves Article Processing Charges (APCs). Authors or their institutions pay publication fees that replace or supplement subscription revenue. Charges vary dramatically—from modest fees at smaller journals to thousands of dollars at high-impact venues.

Critics note that APCs can create barriers for researchers without institutional funding or grant support. Authors from less-resourced institutions or countries may face disadvantages when publication requires upfront payment. Many journals address this through fee waivers or discounts for authors demonstrating financial need.

The "Hybrid" Problem #

Some subscription journals offer gold open access for individual articles upon APC payment—the "hybrid" model. This creates "double dipping" concerns: institutions pay subscriptions for journal access while authors also pay APCs for individual article access. Many funders now refuse to support hybrid publication fees.

Green Open Access (Self-Archiving) #

Green open access involves depositing article versions in repositories—institutional repositories, disciplinary archives, or preprint servers—while the journal may or may not be open access itself.

Authors typically self-archive preprints (pre-peer-review versions) or accepted manuscripts (post-peer-review, pre-formatting). Most publishers allow this with some restrictions, such as embargo periods before the manuscript can be made public.

Repository Types #

Institutional Repositories: Universities maintain repositories for their researchers' outputs. Institutions may mandate deposit to ensure their research is preserved and accessible. DSpace and EPrints are popular platforms for institutional repositories in India and globally.

Disciplinary Repositories: Subject-specific archives serve particular fields. arXiv (physics, mathematics, computer science), PubMed Central (biomedical), SSRN (social sciences), and others provide centralised access points for researchers in those disciplines.

Preprint Servers: Platforms like bioRxiv, medRxiv, and OSF Preprints enable rapid sharing of research before peer review. Preprints don't replace journal publication but accelerate dissemination.

Green Open Access Limitations #

While green routes expand access, they come with constraints. Embargo periods delay public availability. Repository versions may lack final formatting, pagination, or journal branding. Discoverability varies depending on repository infrastructure and indexing.

For journals, green open access through author self-archiving represents a complement to—not replacement for—sustainable publishing models.

Diamond Open Access #

Diamond (sometimes called "platinum") open access eliminates reader fees and author fees. Neither subscribers nor authors pay; instead, institutions, societies, grants, or volunteers cover publishing costs. This model has gained significant attention as concerns about APC sustainability grow.

How Diamond Journals Operate #

Funding sources vary widely. Academic institutions may support journals as part of their scholarly communication mission. Learned societies publish journals as member services. Government or foundation grants underwrite operations. Volunteer editorial labour, often from academics whose institutions effectively subsidise their time, keeps many diamond journals running.

The Diamond Landscape #

Diamond open access is more common than often recognised. A 2021 study found that diamond journals represent a significant portion of open access publishing, particularly in humanities, social sciences, and journals based in Latin America, Asia, and Africa. Many Indian journals operate on diamond models, supported by universities or scholarly societies.

Sustainability Challenges #

Diamond publishing's reliance on institutional support or volunteer labour creates vulnerability. Funding changes, editorial burnout, or institutional priority shifts can threaten journal continuity. Professional infrastructure investment helps diamond journals maintain quality and stability.

Bronze Open Access #

A less formal category, bronze open access describes articles freely readable on publisher websites without clear licensing. The content is accessible but without explicit permissions for reuse, redistribution, or archiving. This ambiguity limits bronze content's utility compared to properly licensed open access.

Some bronze access is temporary—publishers may make content free during promotional periods or after embargo windows. Without formal licensing, users cannot confidently build upon or redistribute this content.

Comparing Models: What Matters for Publishers #

Revenue Sustainability: APC models generate predictable per-article revenue but require author payment infrastructure and waiver policies. Diamond models need stable institutional or grant support. Green routes don't address publisher costs directly.

Author Accessibility: APCs can exclude unfunded researchers. Diamond eliminates financial barriers for authors. Green access depends on author initiative and institutional repository infrastructure.

Funder Compliance: Many funders now mandate immediate open access with specific licenses. Gold (with appropriate licensing) and green (without embargoes) can satisfy these requirements. Diamond naturally complies when properly licensed.

Indexing and Discovery: DOAJ indexes gold and diamond journals meeting their criteria. Green repository content may or may not be indexed alongside journal publications. Proper metadata and licensing affect discoverability across all models.

The Indian Context #

India's research output has grown substantially, creating both opportunities and challenges for open access publishing. Government initiatives have promoted open access, and many Indian journals operate on diamond models through university or society support.

UGC-CARE list requirements have driven journal quality improvements but also created pressure that sometimes leads to problematic publishing practices. Legitimate journals must distinguish themselves through genuine quality and transparent operations—regardless of which open access model they employ.

Infrastructure investments—in professional journal platforms, proper metadata systems, and sustainable hosting—help Indian journals compete globally while serving their communities effectively.

Choosing Your Model #

The "best" open access model depends on your specific circumstances:

For society journals: Diamond open access often aligns well with member service missions. APCs might be appropriate if members expect journal access as a membership benefit while non-members pay.

For institutional journals: Diamond publishing with university support can work well, particularly for journals serving specific disciplines or regional communities. Ensure institutional commitment is stable enough to sustain long-term operations.

For new journals: Diamond models avoid the challenge of convincing authors to pay before a journal has established reputation. Once reputation builds, APC transitions become possible if desired.

For commercial publishers: Gold APC models or subscription-green combinations are common. Market positioning and competitive dynamics influence pricing and policy decisions.

Technical Requirements Across Models #

Regardless of business model, open access journals share technical needs: reliable hosting, professional platforms (OJS is widely used), proper metadata and DOI registration, licensing clarity, and long-term preservation planning. These infrastructure investments support sustainability across all open access approaches.