In another paper published by Xu and Enomae, a simple and quick fabrication method for hydrophobic barriers in μPADs was developed using an inkjet printer to print a modified poly(styrene-co-acrylic acid) solution. Confocal laser scanning microscopy and scanning electron microscopy were used to analyze the hydrophobic barrier. To prevent liquid analyte evaporation during long-distance delivery and analysis, experiments were conducted on various conventional parameters in papermaking processes. Automatic scanning absorptometry was used to measure volumetric flow rates of channels with different internal channel widths, fiber orientations, plasma-etching treatments, beating degrees, and calendering. The results showed that internal channel width had no effect on the longitudinal flow rate, while channels aligned in the machine direction had higher volumetric and longitudinal flow rates than those aligned in the cross direction. Plasma-etching treatment increased the longitudinal flow rate, but not the volumetric flow rate.