Visualizations have been an ongoing object of research within STS. More recently, digital visualizations have become a research method, as in the cases of controversy or issue mapping. Yet generally little attention is paid to the capacities of visualizations in their actual making. Through examination of a practice-based research project on the visualization of air pollutants in Madrid, it can be argued that the design and production of digital visualizations can be framed as a non-representational research method, as well as a means to explore STS topics. On the one hand, during the production of the visualization, the socio-technical assemblage of air pollutants emerges, and therefore its networks and power relations can be accounted for. On the other, their making is a means to interfere in the world. This interference is analyzed by looking at the realms that the making of the visualization brings together, such as environmental research, media art, or collaborative production. Also, through the design decisions, alternative and speculative landscapes of pollution can be formulated, which call for other imaginaries and practices to engage with air pollution.