Linen is valued for its sustainability, but its inherent antibacterial properties remain controversial. This study investigated whether fabrics combining cotton (warp) and linen (weft) in a satin weave have an antibacterial effect. The most important textile properties were analysed, followed by a numerical and visual assessment of bacterial adhesion and 24-h biofilm formation of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. The results showed no antibacterial activity of the fabric, despite the lignin content of 1.11%, which is often associated with antimicrobial effects. Instead, the fabric provided a favourable environment for bacterial growth, particularly for the Gram-positive strain S. aureus compared to Gram-negative strains P. aeruginosa and E. coli. These results show that cellulose-based blends do not naturally inhibit bacterial colonisation and highlight the need for functional finishes to ensure hygienic performance.