This paper addresses the various issues of critical dimension (CD) measurement methodology for mask manufacturing today, and suggests a new approach for standardization of CD process monitors, process improvement/development, and process capability calculations. The sampling method -- both number and location -- used to measure CD performance has become more crucial to high density, fine line device fabrication. Unfortunately, most of the mask manufacturing industry still use either CD cells or a few special CDs located outside the device area to define how well the reticle's CDs meet the specifications. As an alternative, for process monitoring, process improvement/development and process capability calculations, we suggest using an `artifact,' a specially designed test mask. This mask allows measurement of a large number of CDs in order to accurately calculate the mask CD control. Using an `artifact,' process engineers can characterize CD patterns in their processes and can make better informed decisions. Unusual patterns in the CDs are more easily recognized with artifact data and, therefore, can be analyzed more efficiently. By measuring process capability with artifact CD data, rather than with product CD date, customers and management can be provided with a more accurate measure of the CD performance of a mask manufacturing line. In this paper, the application of artifact CD data to measuring the capability of a process to meet a CD performance specification is studied in detail.