Keywords

• In seventeenth-century Rome the prices for paintings were often not established in advance. Notarial contracts were rare
• but private written agreements might be used for works with a public destination
• such as a church. For private patrons
• painters often worked on the basis of an informal
• and oral
• understanding or without any kind of agreement as to price. It was widely believed that the value of a painting could only be determined upon completion: any work could be refused if it did not satisfy the patron
• who would sometime ask for the opinion of a number of experts in order to settle on a compensation. Valuation of a painting or a fresco was thus a common way of establishing its price. In a world of unwritten rules
• painters not fully aware of them often met with disappointment