The rotational molding processing method for plastics is steadily expanding its product range and market areas. However, a drawback of the process has always been the surface pin-holes and internal bubbles that occur in the products because of the inherent nature of the process. In an attempt to alleviate this problem, a program of research has been carried out to investigate the factors that affect the formation of the bubbles and, more importantly, that influence their removal. This paper describes the results of the first stage of this work and covers variables such as the viscosity of the polymer melt, the nature of the pigmentation, the particle size, shape and distribution in the powder feedstock, the mold release agent, the metal used for the mold, the temperature distribution in the mold, etc. It is shown that the mechanisms of bubble formation and removal can be explained and having done this, steps can be taken to ensure that once formed, the bubbles will decrease in size rapidly. This provides significant advantages in terms of reduced cycle time and improved product quality.