Liquid Crystal Shutter (LCS) 3D glasses (also known as 3D shutter glasses, active glasses, or just shutter glasses) are the selection device commonly used to view 3D stereoscopic content on time-sequential 3D displays. There are many available models of LCS glasses to choose from; although, unfortunately, there can be wide performance differences between these glasses. Ultimately the perceived quality of 3D image viewing depends on the display viewed as well as the performance of the shutter glasses used. The objective of this paper is to define key glasses performance parameters and to present a testing method to help quantify glasses and select between models available. Differences in shutter opening speed and open transparency (shuttering performance) are shown between tested models using the method presented here. Additional differences are noted for other performance parameters and features illustrating that there can be many product differences to consider that do not directly affect shuttering performance.