We develop the concept of boundaries in the context of sales personnel and their counterparts encountering and negotiating these while they undertake work to shape markets and build relationships. Drawing on a case study from production chemistry, we show that market shaping implies a mutual development of relationships, goods and services exchanged, and boundaries. In particular, we show that while relationships can submerge and obscure parts or dimensions of boundaries to other market actors, normal business activities such as testing new products and adapting products to changes in environmental legislation make visible some material dimensions of the exchange object, which can attract attention from other sellers. Visibility finds an ex...