This article concerns itself with the materials' - matter, substance - of material culture. More specifically, it explores the making of bioplastics, by taking account of bioplastics' relationships with the products into which they are made. The author focuses on the processes of bioplastics' industrial production and manufacturing into bioplastic products, in and through which bioplastics come to be as they are in our daily lives, and as places where material-product relationships are formed. Her analysis of these processes shows that making of bioplastics is a specialization towards products by achieving compromises among the capacity of materials, conventions about the particular product and its production route, and various interests of the stakeholders involved. As such, she conceptualizes materials as temporally specific phenomena and aims to show that attending to material-product relationships points out new sets of relationships in the make-up of materiality and opens up new pathways of enquiry for material culture studies.