This paper focuses on the commercial activity of colourmen and other purveyors of painters’ materials during the 19th century. After a brief overview of this business, which derived from a branch of the grocers’ corporation and became an autonomous trade at the end of the 18th century in Paris, it describes the important part played by colourmen in painters’ and connoisseurs’ day-to-day life. Then it endeavours to build a category of these shopkeepers, sharing characteristics with both craftsmen and retailers, based on the different products and services they used to provide, and the customers they were aiming at. The analysis of a set of maps describing 19th century colourmen’s spatial evolution every forty years in two cities of different size (Paris and Tours), emphasizes how their urban dynamics can be, on the long term, significant of the trade’s socio-economic gradual changes in both cities.