Sappan and Tingi Wood as a Dye for Gmelina (Gmelina arborea Roxb.) and Lento-Lento Wood (Arthrophillum diversifollium) at Different Coloring Duration

This study investigates the effects of dyeing duration and soaking pre-treatment on the coloring performance of Sappan (Caesalpinia sappan) and Tingi (Ceriops candolleana) dyes applied to Gmelina (Gmelina arborea Roxb.) and Lento-lento (Arthrophyllum diversifolium) woods. Test samples were prepared, pre-treated by soaking at 80°C for 24 hours to remove extractives of the wood, and then colored using Sappan and Tingi dyes at 80°C for 6 and 12 hours. The depth of dye penetration was measured using a stereo microscope, and color variations were assessed using the CIELab color space. Gas chromatography-mass spectrometry (GCMS) was employed to analyze the constituents of the wood, dye material, and colored wood. The results indicated that Sappan dye exhibited greater penetration compared to Tingi dye in both wood types, with deeper penetration in Gmelina than Lento-lento wood. Interestingly, both dyes penetrated more effectively during a 6-hour dyeing period than a 12-hour one. Pre-treatment did not significantly influence dye penetration depth. Color analysis revealed that both dyes imparted a strong red color to the wood, with Sappan producing a more intense red and Tingi exhibiting a yellowish tint. GCMS analysis confirmed the presence of flavonoids, polyphenols, and phenolic compounds in the colored wood samples. These findings contribute to the optimization of natural dyeing techniques for sustainable woodcraft applications.