Since 1750, social, political, and technological conditions have dramatically transformed the trading of commodity goods. Through advances in measurement and communication, previously differentiated products have been transformed into fungible commodities that can be traded on paper and at great distances. These products and the markets where they are exchanged have become terrain for speculation, risk management, and even political negotiation. . . . We believe that these practices of measurement and exchange are at the heart of the process of commoditization: it is the mathematics and measurement of grading and trading that turns specialty goods into interchangeable commodities. . . . Bringing together scholars working on an array of different goods will help us to explore the topics of grading and trading in international perspective, illuminating the comparative ways market norms and practices have shaped both local economies and global politics.