This paper sets out to generate a better understanding of the materials and practices of market-makers. To be internationally competitive, organisations imagine, envision and represent competitive strategies for existing and new markets. Some firms have achieved this through the development of new and innovative business models. When business models are used as frames to create shared understanding of how a firm makes money, they can help managers work out the next innovative steps to make and shape markets. Yet despite our increasing understanding of the components and elements that managers model when developing their business, we know very little about the micro-level representational practices that underpin their development and use. Lynch and Woolgar (1988) offer useful insights into the representational practices in science but argue for a much deeper understanding of the links between emergent and unfolding 'chains of representation' in order to explain how we 'know' something. This papers draws on these ideas of knowing how to act, by seeking to understand the representational practices of managers in their market-making activities. Findings are presented from a two year study that follows a business model circulating to make an IT communications 'Safety Market'. The research explicates representational practices in the process of ‘translating’ a business model into marketing strategy and action. The paper shows how a business models is re-presented and used as a calculative, market-making device, appearing in different forms for different audiences.