The Tyrolean ice mummy known as Ötzi presents some of the earliest direct evidence of tattooing in the human past. Despite decades of study, it remains unclear how the Iceman's tattoos were created and what tools and methods were used. Popular discussions of the Iceman describe his tattoos as having been made by incision, first cutting the skin and then rubbing in pigment from the surface. The authors review the scholarly literature on the Iceman's tattoos and summarize ethnographic, historic, and anthropological research on global patterns of tattooing to contextualize the Iceman's marks within pre-electric tattooing traditions. The results of recent experimental tattooing studies are then compared to the physical signature of the Iceman's marks to evaluate existing claims and provide informed hypotheses as to how those tattoos were created.