Open Science
Green open access (self-archiving a manuscript in an institutional, funder, or subject repository) is a widely accepted practice in research communication. We know that authors aren't always aware which pathways are open to them, and this article aims to provide additional guidance.
Institutions and funders across the globe are working to increase the adoption of green open access (OA) among their researchers. The goal of green OA, sometimes known as public access, is to provide the general public with free and transparent access to research outputs that serve the public good and are often the result of public funding. This broader access is centered on authors uploading their accepted manuscripts to publicly available repositories.
Publishers, including ACS Publications, have provided authors with a variety of ways to make their published research available in green OA repositories, including 'green via gold', embargoed green open access, and zero-embargo green open access pathways. You can find more information about each of these pathways below.
In This Article:
Green via gold
Embargoed green open access
Zero-embargo green open access
Publishing Pointers: Version of Record vs. Accepted Manuscript
- Version of Record: The final, peer-reviewed version of an article that is published in a journal, designed for maximum readability and discoverability. This includes formatting in the style of the journal, in-line figures and tables, technical editing, hyperlinks to citations and other relevant data, and long-term indexing and preservation.
- Accepted Manuscript: Sometimes called the Author Accepted Manuscript (AAM), this is the final version of an article following peer review and revision, but before it undergoes design, technical editing, typesetting, and other important processes designed to maximize readability and utility. Accepted manuscripts are largely unformatted, may be missing in-line figures and tables, and lack other features that make them easily readable and discoverable by readers.
Green via gold
When authors publish their article as gold open access, the version of record (the definitive version of the article as it appears in a journal, in a format which is preferred by readers, and regarded as the most trusted version for citations) is made immediately available without requiring a subscription. Readers are also free to redistribute the version of record of open access articles as long as they provide appropriate credit to the original authors. Depending on the Creative Commons license the article is published under, readers may also be able to remix or create derivative works from the article.
There has been significant growth in gold open access over recent years, largely driven by increased participation in read and publish agreements, which are arrangements between publishers and institutions that provide full reading access to subscription content and full or partial coverage of open access article publishing charges (APCs) for affiliated authors. For example, researchers at over 1,600 institutions worldwide benefit from access to ACS Publications read and publish agreements.
Publishing an article in an ACS journal as immediate gold OA, whether through a read and publish agreement or by covering the APC through other means (such as grant funding), also includes the ability to self-archive the accepted manuscript at no extra charge—fully meeting most research funders' and institutions' requirements around open access.
Embargoed green open access
Historically, self-archiving of the accepted manuscript has been available without any charge for authors who are willing to wait until the expiration of an embargo period when publishing the version of record without immediate open access. In the case of ACS Publications journals and many other publishers in STEM fields, this embargo period is 12 months from the date of publication, and allows publishers to recoup the costs of publishing services by collecting subscription fees.
Authors are free to upload their accepted manuscript to a repository prior to the expiration of the embargo period, providing that the repository does not make the manuscript available for public download prior to that date. (Most repositories allow authors to restrict access to uploaded content until a specified date, and/or will automatically remove access restrictions a year after the document is first uploaded.)
Though many research funders and assessment frameworks specify that accepted manuscripts must be made available immediately upon publication, it's often possible for authors to claim an exemption for specific manuscripts. For example, the UK's Research Excellence Framework (REF) 2029 provides an exception for authors. They may submit articles that are subject to a 12-month embargo and still remain compliant if they believe the journal in which they're published is the best venue to disseminate their work.1
Zero-embargo green open access
As the term implies, "zero-embargo green open access" refers to providing immediate access to the accepted manuscript as soon as the version of record is published. The overwhelming majority of publishers do not permit authors to follow this path, directing them to choose between either "green via gold" pathway or embargoed green OA.
ACS Publications introduced a zero-embargo green open access option in late 2023 to meet the needs of authors who are required to immediately self-archive their work, but who do not wish (or have insufficient support) to publish the version of record as gold OA. Authors can request this process by noting in their cover letter or manuscript that they want to immediately post the accepted manuscript to a repository. Payment of the fee for zero-embargo green OA is due after the manuscript is accepted for publication. Authors in qualifying countries are also eligible for special pricing for this charge. As noted above, this pathway is not applicable to authors who publish the version of record as gold OA (either through a read and publish agreement or using alternative funding methods), as zero-embargo green OA is already included if the version of record is published as open access.
Establishing a pathway for zero-embargo green open access has also led to a number of "read and green" agreements, widening the pool of research immediately open to a global audience, and speeding the transition to OA.
Providing you with a pathway to green open access
ACS Publications supports several different routes to green OA. These have been designed in partnership with the global research community to provide every author with an approach that meets their needs, ensuring they can both publish their research in their preferred journal and achieve any self-archiving requirements.
In the majority of cases, authors publishing in ACS journals have access to green OA pathways at no cost to them—either by publishing under a read and publish or “read and green” agreement, or following a 12-month embargo period.
If an author isn't covered by an existing agreement and indicates their intent to make the accepted manuscript immediately openly available without embargo (either in the manuscript or a covering letter), their manuscript will then be reviewed and our Open Access Operations team will contact the author to discuss their green OA options.
If you have any further questions about which pathway is best for you, please don't hesitate to contact us.
References
- REF 2029 Open Access Policy, retrieved 04/08/25: https://2029.ref.ac.uk/guidance/ref-2029-open-access-policy/#section-policy-exceptions