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Pin holes of film produced in plating are generally observed by measuring their number and size, but it is very troublesome to do so. Therefore, a new method to measure pin holes, checker board-like sieve method, was introduced. By this method, it is found that the pin holes can be measured more speedly and accurately. By regulating the size of sieve, the errors of this measurements can be decreased.

In order to minimize the amount of dragout and to obtain the reproducible data, behaviors of factors affecting the drawing amount should be studied. Among many factors involved, physical properties of plating solution, such as viscosity and surface tension, and the shape of edge of specimen were investigated in the present study.The effect of viscosity on the amount of dragout changes according to the speed of withdrawal or to the thickness of the liquid film. Decrease of surface tension increases the volume of drainage and decreases the volume of bead on the edge. With the surface tension less than 40 dyne/cm the amount of bead of edge becomes constant regardless of thickness of adhearing film. The amount of bead of the dragout is generally more than 50% of that of static drainage.