There are two main routes to open access publishing; the open access journals and the open access repositories or open archives and these are described as such:

• Gold route

  - Gold route or full open or gold access journals are those that all the published scholarly articles are open and freely available to the public. Publishing in these journals is subject to Article Processing Charges, and the cost is covered either by the author and his/her institution or by the research funder.

  - Hybrid scientific journals adopt a dual-publishing model, encompassing both open access and subscription-based access to scientific publications. Open access publication in hybrid journals is subject to a publishing cost known as (Article Processing Charges, APCs).

• Green route
  
  

  The green route of open access involves the authors self-archiving their scientific publications in an institutional or subject repository. Additionally, authors should consult the publisher's policies regarding the embargo period of their publications. For publications funded by European Union programs, there is a provision for a 6-month embargo period in Natural Sciences, Technology, and Medicine disciplines, and a 12-month embargo period for Humanities and Social Sciences.

Agreements Covering Publication Costs

The Hellenic Academic Libraries Link (HEAL-Link) actively supports Open Access publishing by negotiating agreements with various publishers to cover publication costs (Article Processing Charges, APCs) either partially or in full.
Below is an overview of the available agreements, including their key terms and conditions:

Eligibility Criteria

To qualify for a full or partial waiver or a reduction in publication costs, the corresponding author must:

• Be a member of the National Hellenic Research Foundation (NHRF) research staff.
• Indicate the National Hellenic Research Foundation as their "affiliation" when submitting their manuscript on the publisher's platform.
• Use their institutional account for submission.

Additional Resources

For more information on Open Access agreements and eligible journals, visit the following HEAL-Link pages:

• Index of Eligible Open Access Journals: https://scholarly.heal-link.gr/oajournals/ – A list of journals covered under cost coverage agreements.
• Open Access Agreements Guide: https://scholarly.heal-link.gr/guide/ – Details on:
• Eligibility criteria
• Submission process
• Recommendations for the Acknowledgment section

These agreements provide researchers with greater opportunities to publish their work openly, increasing visibility and accessibility within the academic community.