PURPOSE There are a number of techniques currently being used for measuring plating thickness. All have peculiar application and also limitations@ Basic economics@ however@ demands that for measuring gold thicknesses in the commonly used plating thickness ranges@ a system must be highly reliable@ accurate@ repeatable and fast. Over the past several years X-ray Fiuorescence systems@ more than any other@ have been found to meet that requirement. There are@ however@ many facets of operation involved with x-ray techniques with which the operator should be acquainted. The purpose of this paper is to highlight these subtleties so that x-ray users are aware of them and can implement procedures for their instrument operation which will provide measurements of highest possible levels of accuracy and repeatability.