Overlay journals: a study of the current landscape

Overlay journals are characterised by their articles being published on open access repositories, often already starting in their initial preprint form as a prerequisite for submission to the journal prior to initiating the peer-review process. In this study we aimed to identify currently active overlay journals and examine their characteristics. We utilised an explorative web search and contacted key service providers for additional information. The final sample consisted of 34 overlay journals. While the results show an increase in the number of overlay journals in recent years, the current presence of overlay journals is diminutive compared to the overall number of open access journals. The majority of overlay journals publish articles in the natural sciences, mathematics or computer sciences. Overlay journals are commonly published by groups of academics rather than formal organisations and overlay journals may also rank highly within the traditional journal citation metrics. None of the investigated journals required fees from authors, which is likely related to the cost-effectiveness of the overlay publishing model. Both the growth in adoption of open access preprint repositories, and researchers willingness to publish in overlay journals will determine the models wider impact on scholarly publishing.