Concerning the white particles, the highest quality obtained was from using SPR VI, which has a ratio of zinc carbonate to tergitol NP-7 of 12.5. The proportions of particle and detergent were 10 and 0.8%, respectively. However, this solution was quite effective only on the metal plate surface and the quality of the ridge counts in the developed latent print (on every type of surfaces) were not good (6.6) (Table 1). Thus an improvement of this formula is necessary. In contrast to the results presented here, it has been shown that titanium dioxide, zinc oxide and zinc carbonate can be used as effective particles in a SPR suspension,(7) in contrast to the results of this study. The differences in the quality of the ridge counts might due to the particle size and oxide concentration. To improve upon the SPR VI formula, a reduction in the size of zinc carbonate particles, or a suitable proportion of particle and detergent as well as ratio of the two, or the use of a 10% (v/v) Aerosol OT solution(8) or Kodak Photo Flo-200(9) as the detergent should be considered. Since Photo Flo helps the Small Particle Reagent to mix into solution or suspension.