THE finishing of automotive products with lacquer is still in the transition stage, according to the author. Sufficient time has not elapsed to provide an adequate background of experience which establishes principles and practices that fully meet the requirements of the production engineer. In other words, many of the things we think we know about lacquer finishes and lacquer undercoatings are either not true or are correct in part only. The general function of a surfacer is to provide a smooth surface for the finishing coats. Inasmuch as the larger part of the material applied to provide such a surface must be cut away by sanding so as to bring the surface as a whole to the requisite smoothness, a satisfactory surfacer is one that can be applied with the minimum effort, can be sanded with the minimum amount of labor, and can be purchased cheaply, the reason being that most of it is carried away by the wash water during the sanding process.