As the most porous substrate (average pore size 5-50μm), paper absorbs ink rapidly through capillary action with penetration depths of 20-120μm. High-speed thermal inkjet (TIJ) systems achieve 600dpi resolution on packaging labels at line speeds up to 300m/min, while piezo drop-on-demand (DOD) printers handle corrugated boxes with fast-drying UV inks (curing time0.5s). The key challenge lies in preventing feathering – mitigated through solvent-based inks with 15-25% glycol ether content for controlled penetration, particularly critical for barcode legibility meeting ANSI X3.182 grade B requirements.