This article investigates ethnic boundary perceptions among people without a migration background living in majority-minority neighbourhoods in six western European cities. The main research question is whether people without migration background who have contact with migrant groups in their everyday life surroundings perceive ethnic boundaries as blurred (i.e. individuation) or as bright (i.e. culturalisation). The main argument of this article is that boundary perceptions are importantly shaped by the specific urban micro-setting in which people come into contact with migrant groups. Drawing on data from a large-scale survey conducted in Amsterdam, Antwerp, Hamburg, Rotterdam, Malmo and Vienna, the study examines how urban micro-setting affects ethnic boundary perceptions (i.e. individuation or culturalisation). The results show that contact with migrant groups in parochial spaces is significantly and strongly related to the blurring of group boundaries (i.e. individuation), while exposure in public spaces has no significant effect on boundary perceptions.