• Spruce bark extract and tannic acid are potential biocoatings for medical textiles. • Bark extract coatings show superior antiviral activity against CVA9 and HCoV-OC43. • Tannic acid coatings show potency against E. coli , S. aureus , and MRSA bacteria . • Draw-down coating enables the strongest antibacterial and antiviral textile efficacy. • Coating morphology and fiber–polyphenol interactions governed bioactivity. Polyphenol-rich Norway spruce bark extract, a side-stream from the forest indu