Language: Dayak
Source: Period sources

Description

Kemalau, also known as gutta-percha, is a natural thermoplastic latex made from the sap of the Palaquium gutta tree.¹

Among its many uses, it was used to join the blade of the mandau sword of the Dayak of Borneo to its hilt.

A Dayak mandau hilt, made of carved deerhorn.
The black substance between rattan braid and blade is kemalau.

Notes
1. S.W. Tromp; Mededeelingen omtrent mandau's. Den Haag, 1887. Published in Internationales Archiv für Ethnographie,  International Gesellschaft für Ethnographie; Rijksmuseum van Oudheden te Leiden, 1888. Volume 1, page 24.