This thesis is a study of the role of material forms as mediators of cross-cultural encounters in the Trobriand Islands. It is based on eighteen months of ethnographic research in Kiriwina and other parts of the Massim region, Milne Bay Province, Papua New Guinea. The dissertation analyses previously overlooked material expressions in the form of woodcarvings for sale (tokwalu) to outsiders. Throughout the thesis, I demonstrate how Trobrianders conceive tokwalu as symbolic and material tools for the apprehension of what is becoming an increasingly de-territorialised universe. Woodcarvings are deployed as instruments of indigenous analysis and native agency in an attempt to establish and control the local-translocal flows that shape social life in the Massim. Despite early contact and their ongoing engagement with the wider world, the Trobriand Islands are commonly portrayed as a place where cultural resilience and the continuity of traditional models of livelihood prevail over social change. Yet like elsewhere in Melanesia, Trobrianders face the transformations effected by dynamic processes of cultural, social and economic globalisation impinging upon their region. Overpopulation, food security issues and the partial collapse of traditional hierarchical structures have elicited the assemblage of new relational networks to negotiate these transformations. Tokwalu are not fixed signposts in a predefined system of meaning but changing materialisations of contrasting images and intentions within these networks. They bring together traditional symbols and modern elements in an effort to remain commensurate with what outsiders expect from local carvings and what local carvers expect from outsiders. Vehicles of desires and aspirations, woodcarvings project Trobriand personhood and appropriate alterity as an ideal, modern other. Ultimately, towkalu are empowering artefacts for locals. They allow them to buy food, get healthcare, obtain education, increase their social prestige, enhance their mobility and fulfil customary and new obligations. This research places this native view of tokwalu at its centre to posit the necessity of considering material assemblages as processes of indigenous analysis and action in Melanesia, without which our understanding of these processes remains severely curtailed.