This study complements our investigations into the use of accounting manuals as representations of commercial activities. Our previous work focused on the Guide du Commerce of Gaignat de l'Aulnais and the slave trade in eighteenth-century France. We broaden our scope with cross-sectional archival evidence to examine the extent to which the methods and operations in these sources point to a collective knowledge shared amongst traders and those engaged to conduct the slave trade on their behalf. Of particular interest is the prevalence of standardised methods, documents and terms of trade, all of which point, in a similar way to that of the Guide du Commerce, to the slave trade's technical contributions to capitalism (Petre-Grenouilleau 2004, 352). The archival evidence illustrates the rationalisation and institutionalisation of an economic system, albeit a particular outlier, and its progressive sophistication in terms of operating processes, creating thereby the illusion of a rational business model.