The screen-printing and conducting performances of carbon black (CB)-based pastes depend sensitively on their rheological and electrical properties. We employ rheology and impedance spectral analyses to systematically explore the dynamic percolation behavior of a series of model CB/EC (ethyl cellulose) pastes under the influences of CB concentration and system temperature. Rheological spectra reveal excellent superposition for results with varying CB concentration, system temperature and aging time, suggesting the formation of universal (fractal) microstructures during the dynamic percolation process of CB clusters. The corresponding impedance spectra reveal a notable increase in both permittivity and ac conductance, along with three major relaxation modes. Detailed analysis of the aging-time dependence of the individual relaxation mode reveals, however, that CB concentration and system temperature have distinguishable impact on the percolation network at varied length scales. As a practical assessment, the measured electrical resistances of screen-printed lines using the CB pastes above exhibit a moderate yet systematic reduction, albeit not as pronounced as the changes noted previously in rheology and impedance spectra on the original paste samples. Overall, this study implied that combined rheology and impedance spectral analysis provides a sensible and complementary means to resolve the percolation behavior and screen-printing/electronic performance of conducting pastes.