Ijuk
Definition
Sugar palm fibre (Arenga pinnata) — coarse black fibres harvested from the trunk of the sugar palm tree, used traditionally as a roofing material and water-resistant thatch. Ijuk is highly durable, naturally resistant to rot and insects, and was the primary roofing material for sacred buildings in Bali and parts of Java before corrugated iron became dominant. It remains the required material for meru shrine roofs in Balinese temples, where authenticity is culturally mandated.
Example
The meru towers at Pura Taman Ayun in Mengwi, Bali, are roofed with ijuk thatching that requires specialist craftsmen to replace every 20–30 years — the material's longevity and its dark, textured surface giving the shrine towers their characteristic silhouette against the tropical sky.