Discussions of openness in the cultural heritage sector often do not acknowledge that “all forms of openness entail forms of closed-ness” (Edwards 2015, 253). We need more sensitivity to what is gained and lost with different framings of openness. In the cultural sector, openness has political as well as practical implications, and associated closures, that require attention. This paper draws on the experiences of the National Galleries of Scotland (NGS), gathered in the form of research interviews in late 2016 and internal reflections on a major project to redevelop the NGS website. We explore the extent to which particular emphases around openness, including copyright and the need to focus on digitizing collections, took priority over other important issues, such as open data and standardization. We characterize NGS’ strategy as one of "progressive openness." The underlying infrastructure of the website was developed to eventually facilitate sharing of data via Web services to other projects or digital outputs, for example, ArtUK and Europeana, making it technically possible to expose and share data. However, this functionality and its implications were not well understood within the institution, and the widely shared vision of openness did not always include possibilities for making material available beyond the boundaries of the website. Assumptions about the website as the core location for digital objects left some opportunities underexplored, such as the opportunity to think beyond this website to the other places, times, and contexts in which people might encounter the collections online. Strategic attention to and awareness of open data, standardization, and the licensing of textual materials do not necessarily flow naturally from an orientation and commitment to openness. This paper explores this dynamic, and discusses how organizations might consider their own "boundaries of openness."