“Eco-labels” are an increasingly important form of private regulation for sustainability in areas such as carbon emissions, water consumption, ethical sourcing, or organic produce. The growing interest and popularity of eco-labels has also been coupled with growing concerns about their credibility, in part because the standard-setting and conformity assessment practices that eco-labels adopt exhibit striking differences. In this paper, we assess which assurance practices contribute to eco-labels being perceived as better governed, in the eyes of experts as well as the media. Unlike previous studies, which are mostly conceptual, qualitative, or focused on one or few eco-labels, we study a large set of eco-labels, combining data from three different sources. Our findings suggest that experts and media are primarily concerned about “re-assurance” practices, looking for one or preferably multiple layers of “re-assurance” that independent parties are overseeing the eco-label and the firms certified under it.