The purpose of this study was to determine the effect of the ultrasonication process on the performance of fiber cotton coloring with sappanwood (Caesalpina sappan Linn) extract. This study used a Factorial Complete Randomized Design (RALF) with two treatment factors which each treatment was repeated three times. A-factor was frequency (20 kHz and 40 kHz) and B-factor was ultrasonication time (…