The notions of user involvement and user orientation have become popular catchphrases in innovation research and practice. Central in this research are the ideas that knowledge about users leads to better design, and that the interests of users and producers need to be aligned. In another field of research, scholars have long recognised the significance of metaphors for integrative pursuits. However, to date these two literatures have not been combined into an integrated framework. Producing such a framework for understanding the process of interest alignment is the main task of this paper. Illustrating the framework with a recent probiotic innovation process, this paper argues that "learning to match" type of boundary--syntactic, semantic and pragmatic--faced between users and producers with type of capability is crucial for bringing about successful user-producer integration. This paper also argues that "learning to blend" forms a central part of the semantic capability. (Contains 7 figures and 3 notes.)