The use of design artefacts in research is a debatable topic which raises important questions about the different approaches to design research and legitimate ways of knowledge production. Research through design normally involves construction of a design artefact, which is at the core of the research process. This paper will outline some characteristics of artefacts that come out of such research practices, seeking to form a base for understanding the nature of research design artefacts and their evaluation. We will examine the process of translation from the research question into the design brief, into the prototype, back to the question, back to the prototype; until the design artefact is fit as a tool for research; or is (temporarily) discarded. The artefacts produced in this way do not necessarily serve a utilitarian purpose, but provide an explicit feedback about their use and the experience they invoke. In terms of design, they are like code with a lot of debugging print statements. They possibly never leave the studio and when they do, different levels of independence from the studio setting can be identified.