The paper identifies and tries to account for the forms taken in selected art markets for the selling of paintings, as a response to specific features and constraints in the local regulatory environment. Our analytical histories cover 15th century Bruges, 16th century Antwerp, 17th century Amsterdam, and early 18th century London and Paris. They yield some evidence that : (1) restrictive guilds did not succeed in stifling innovation. though innovators were forced to take indirect routes and to adopt forms not always the most efficient; (2) where circumstances allowed a choice of auction form (English or Dutch) the method selected matched the prior experience of buyers (low or high respectively) ; and (3) in the single instance where guilds were open to cooperation across skill categories this coincided with a series of marketing experiments and a range of novel products.