This study investigates how the fringing field affects the total current flow within a conducting polymer. In order to extract the fringing field component of bar pattern resistors, a solvent-assisted patterning method using subtractive photolithography was successfully established for the conducting polymer poly(3-hexylthiophene). By comparing the current quantities of unpatterned and patterned resistors, a conductance factor for the fringing field was calculated, proving to be almost constant regardless of the resistor length. It is therefore concluded that the length as well as the width of the conducting polymer film need to be suitably patterned for the precise operation of organic electronic devices. In this regard, the patterning method developed will be useful for the fabrication of micro-scale devices.