The paper discusses how a teaching approach, "interdisciplinary design and invention pedagogy," affected primary school student teachers' learning outcomes through the craft design process in pre-service teacher education. This study applies developmental work research (Engeström in J Educ Work 14(1):133-156, 2001; Engeström in Yhteiskehittely ja vaihdon vyöhykkeet tutkijoiden ja elinkeinoelämän välillä 2013; Galison in Image & logic: a material culture of microphysics. The University of Chicago Press, Chicago, 1997; Gorman in Trading zones, interactional expertise and interdisciplinary collaboration 2005) that aims to develop educators' work involved here. To support a craft-designing process and making innovative artefacts, two disciplines--natural science (physics) and drama--as examples of interdisciplinarity were invited to contribute to the craft process. The craft course on 'smart textiles' was carried out in the spring of 2014 and 2015 at the University of Helsinki in pre-service primary teacher education. The aim of the crafts course was to get student teachers familiar with different dimensions of crafts (textile, design and technology), inquiry-based designing and an interdisciplinary teaching approach to be used in a primary school context. The craft task included working in small groups and designing smart textiles. Student teachers documented their designing and implementation processes through photos and videos using applications such as iMovie or Movie maker. In addition, participants wrote comprehensions of their projects in learning diaries. The data consist of student teachers' learning diaries (N = 17) and prototypes (N = 17), which are analysed by qualitative content analysis. As results, first, the paper presents some innovative artefacts that student teachers created. Second, it describes the learning that emerged in pedagogical thinking of student teachers related to the interdisciplinary designing process, including (1) four interdisciplinary contexts, (2) new pedagogic thinking and (3) change of attitude towards integrative teaching.