Trade fairs and exhibitions have been around for centuries. They provide an important meeting point for sellers and potential buyers, be it for cars or clothes. Some fair organizers partition the exhibition space into predefined units, which may limit the flexibility. A free layout of the space allows for any shape or size of the stands and gives the exhibitor a better chance at creating something spectacular that will attract attention. Providing full flexibility, and thus a free layout, means that every new fair will be different. In addition to each individual stand having a varying size, the shape is not constrained to be rectangular, but might be, e.g., triangular or elliptic. All of this puts high demands on the production of the fairs. For example, the location and outline of every stand has to be determined and marked on the floor before the construction phase. This article gives a real world example of how robot technology can be used to automate the marking process for exhibitions and fairs in a way that both reduces the marking time and improves the working conditions. A mobile robot system equipped with a laser scanner and an ink jet printer is presented. The focus of the article is the description of the marking process and the system design. In addition, the requirements for such a system are outlined as well as results from over three years of operation and an analysis for commercialization.