This document describes the instrumentation, standards, and measurement techniques used at the National Institute of Standards and Technology (NIST) to measure specular gloss. The organization of this document is as follow. Section 1 describes the motivation for establishing a reference goniophotometer and primary standards for specular gloss and associated calibration services that are available. Section 2 presents the theory and measurement equations relevant to the measurements described in this document. The NIST reference goniophotometer including the illuminator, goniometer, receiver, and the characterization and uncertainty analysis of the instrument are described in Sec. 3. In Sec. 4 the new primary specular gloss standard and its characterization are presented. A sample calibration report and references containing details of the instrument and primary standard are reproduced in the appendices.