This paper is written for the newcomer to GC as well as for those who use the method only occasionally. It is based largely on more detailed and lengthy review articles and studies which have appeared earlier (1–4). This paper is written with the idea of providing the reader with information about chromatographic supports which will allow him to make an effective column. In part, the paper contains a great deal of negative information. This is necessary since there are many deficiencies in supports and the reader must be aware of them in order to avoid or minimize these deficiencies. In this article, I will discuss factors that contribute to the preparation of an efficient column and to one that is free of tailing. In doing this, I will examine the structure and surface of the support.