GreyNet’s web-access portal and repository is the GreyGuide – an internet resource that is fully open access compliant. Having benefited from technical developments, the migration of hundreds of metadata full-text records, and the addition of enriched fields and functionality since its launch, the GreyGuide now offers GreyNet a test-bed from which to map and measure its capacity in open access publishing. The population of this study is drawn from digital resources accessible via the GreyGuide Portal and Repository. The selection is based on the criteria that GreyNet is the content provider, that they are open access compliant, that they are sustained information resources, and that there are available use statistics from which to draw upon. This study focusses on the open access to GreyNet’s range of publications, where attention is drawn to the specific document types that meet the sampling criteria.