Non-drip blue gel clings to surfaces. Advanced GEL/Enzyme formulation works quickly. Safe to use, non-toxic, water-based. Easy to apply by brush or roller. Clings to vertical surfaces. One gallon will cover a little over half of a 10 ft x 12 ft room with 8 ft ceiling (approximately 300 sq. ft. or 6 bolts of wallpaper. Coverage will vary with porosity of wallpaper and thickness of production application.