We tried to improve field emission properties of carbon nanotube (CNT) paste emitters by controlling the size distribution of aggregated SiC fillers. The SiC fillers used as an adhesion promoter strongly affects the dispersion of CNT paste, determining uniformity and reproducibility of the field emitter. We found, to date, that the optimum distribution is about 1 μm of D50, the value of the particle diameter at 50% in cumulative distribution. The CNT emitters with the optimized paste showed uniform and reproducible emission performances along with high adhesion to the cathode. The improved paste formulation and emitter fabrication could lead to successful field emission devices and applications.