Large numbers of young Dayak men hailing from remote interior Borneo communities traveled to New Guinea throughout the twentieth century, under various circumstances mostly consistent with their own cultural traditions. Recent research among these men's home communities has brought to light memories and stories about New Guinea and its Papuan residents, as well as photographs and memorabilia, feeding by their evocative power the construction of alternative indigenous Dayak narratives contrasting with those available in Western written sources. In their New Guinea social encounters, Dayak travelers "traded culture", both material and immaterial, with Papuans. Scores of Papuan artefacts must have reached Dayak villages, from where they circulated across Borneo as trade goods, amulets, or souvenirs, some to be found today as "discordant" artefacts in museums' Borneo collections, subject to inquiries about their "biographies" (i.e., their origins and travel histories). The article finally Twentieth-Century Dayak Visitors to New Guinea Annali, Sezione orientale 85 (2025) 156-196 suggests the great interest of a "mirror" research focusing on Dayak cultural heritage, material or not, still dimly traceable among Papuan tribal communities.