This master thesis is the result of the graduation project for the master Design for Interaction at Delft University of Technology and is an attempt to combine two field of research, namely, materiality and (social) interaction design. As this project did not originate from a specific problem but merely from an opportunity for innovation the main focus was on research. This was both theoretical and explorative. The title for this thesis is: Designing for deliberate traces Applying knowledge of material aging to daily life (social) product interaction. Within HCI and interaction design there is a growing interest in bridging the gap between digital interaction and the material qualities of artifacts and environments (Giaccardi, Ciolfi 2013). As computing becomes more transparent and moves into the background (smart objects and environments), designed interactions become embedded into everyday materials and artifacts. Social media in particular has created a new vocabulary of digital social interactions that frames interpersonal communication and the social sharing of personal data. Even though this advanced system stimulate social interaction with its fast, efficient transmission of content, it lack some subtle ways for emotional expression due to the fact that physical interaction over a distance is not yet possible (Wang 2013, Giaccardi 2013). Merging social data, social networks, and socially sensitive interactions with a vision for materiality in computing, can provide a brought perspective on emerging material-oriented design methods in HCI (Giaccardi, Karana 2013). Of course this is not without purpose as the goal is to create meaningful interactions with daily-life object. This could be to create social connectedness or draw social connections but also affecting individual social behavior (Giaccardi 2013). Ranging from one discipline to another, materials are known to be a powerful tool in facilitating tangible interactions. Every material develops a certain look and feel over time, which contributes to a certain aesthetic (Ashby 2002) of the object it embodies. Also the physical nature, structure and endurance of these materials change over time; for example concrete breaks, wood wears out, metals are subject to fatigue (Tehlan 2009). This “aging” stimulates the development of material traces (Rosner 2013, Rognoli & Karana 2013). Material traces have a narrative character (Rosner 2013), they can tell stories about the people that create them and the environments they manifest in (Ingold 2002). The majority of our understanding of the world depends on our ability to tell stories about it. Stories are an important way for us to explain things, exchange information, show our identity and express ourselves within different contexts (Brooks 2003). Storytelling is a natural but yet powerful tool for people to share information about the world. Therefore the narrative character of material traces makes them especially interesting for designers to facilitate meaningful interactions through designing for traces (Rosner 2013, Rognoli & Karana 2013). While attempting to find ways to change the way we design products/materials we take into account Ewalds (Ewald 1996) view on this. Starting with “prudence” (Cucuzella 2010) which refers to how humans deal with situations when they are faced with uncertainty. According to Ewald humans react on situations in 3 ways, which can be seen as reasons for why we would prefer to shift to more conscious design. 1. Foresight, encourages the integration of the future with the present; Focusing on achieving a future goal by changing the current situation. 2. Prevention; developed from a certainty of risk based on the knowledge possessed, changing the current situation to prevent a future risk. 3. Precaution originates from the uncertainty of proof of future, and therefore refers to conditions not covered by either foresight or prevention. All the above, and more, lead to the formulation of this assignment.