Textile materials and textile design are a part of countless products in our surroundings,as well as diverse design fields and industries, each of which has very different materialtraditions and working methods. The aim of this thesis is to add to our understandingof the relationship between textiles and products in the design process, and to explorehow textiles enter and influence product design processes and how products functionin textile design processes. A further aim is to examine the effect of new textiletechnology, such as smart textiles and 3D printed textiles, on this dynamic. This thesis is the result of an interplay between theoretical work, experimentalpractice-based projects, and observation of design practice, and it presents two typesof results: Firstly, descriptions of how the relationship can manifest itself in the designprocess, which give a broad picture of the relationship between textile and productand in so doing add to our understanding of textiles as design materials and highlightsome of the additional complexities and possibilities for the design process that comewith new forms of textiles. Secondly, this thesis presents ways of describing thedynamics between textiles and products in the design process, with the intention ofopening up for reflection on how we design, and can design, with textiles. Here, themain outcome is a theoretical framework which examines the relationship from botha product design and a textile design perspective, and includes methods and questionsthat can be used to explore and define how textiles and products meet in the designprocess.