In the last decade, we have witnessed an unprecedented growth in the globalisation of innovation activities and more specifically, of global innovation networks (GINs) extending into middle-income countries. However, hitherto most of the literature is either theoretical or based on a handful of cases. We do not know what are the different forms of openness through networks in which firms participate whether in terms of the various degrees of global scope, innovativeness and network scope or other key characteristics. This exploratory paper provides empirical evidence of the different forms of openness through global innovation networks used by firms located in mature and emerging innovation systems. The paper relies on survey-based firm-level data collected in five European countries plus Brazil, South Africa, India and China.