The growing interest in developing antibacterial textiles using natural functional agents is largely driven by their sustainable and eco-friendly attributes. Lignin, a highly available biopolymer with a polyphenolic structure, has drawn attention due to its potential as a bioactive antibacterial agent. However, its inherent heterogeneity poses challenges, particularly regarding its antibacterial efficacy. In this study, unmodified kraft lignin sourced directly from the paper industry was applied to cotton and polyester fabrics, using a knife-coating technique with varying concentrations (0%, 5%, 10%, 20%, and 30%