The shift from closed to open paradigms in new product development is seen as an emergence of new forms of production, innovation, and design. Innovation processes are shifting from open source software to open source hardware design. Emulating open source software, design information for open source hardware is shared publicly to enhance the development of physical products, machines, and systems.Similarly, the rise of the “maker culture” enhances product tinkering,while the do-it-yourself (DIY) movement embraces “the open” in design.Users participate in design via crowdsourcing and co-creation on platforms such as OpenIdeo and Quirky and by joining proliferating open innovation challenges. At the back end of the design process, customers are invited to participate in mass customization and personalization to personalize products.The open paradigm has received scholarly attention through studies of open source software and open source hard- ware. Moreover, user engagement in the design process has been studied as user-centric innovation,participatory design,and co-design, as well as customer co-creation and crowdsourcing. However, the “open” landscape in design lacks consensus regarding a unified definition for open design practices. This lack of agreement partially results from the gap in approaches to design. Studies of innovation and new product development are focused on user-centric approaches and customer engagement in several stages of the design process, whereas current definitions of open design are focused on openness of technical design information and largely exclude, in particular, the early stages of the design process. The open design definitions also lack the commercial aspects of openness. Thus, the existing definitions are too narrow to holistically represent the shift from a closed paradigm to an open paradigm in design. Moreover, the lack of clarity and consistency in definitions is hindering the development of open design as a design approach. To fully advance the research on methods and practices, a more comprehensive perception of openness in the design process is needed.