This excellent primer focuses on how densitometers work, how they are used, and and how to verify conformance to standards. It includes discussions of bandwidth, the use of polarizing filters with wet ink films, and improvements in densitometry. Appendices address the use of the Graphic Communications Association's T-Ref, standard lighting conditions, densitometry capability assessment, and the common characteristics of different color measurement systems.

From the Preface: “The need for improved communication of density values has been recognized for many years...[I]t is not only the printer for whom the densitometer is necessary for quality control. It is the advertising agency, the publisher, the cataloger, and the color separator as well. Unfortunately, inter-instrument agreement was not the rule...The lack of a standard response, coupled with differing manufacturer interpretations of the correct response, created communication problems between and among each segment of the print production community and caused doubt about whether densitometric values could be relied upon to provide needed process information. The basis for a solution to the lack of densitometer agreement was finally achieved in 1984 when ANSI...finalized a standard that specifies the spectral response for graphic arts reflection equipment, naming it Status T...”

Target Audience: Personnel involved in a variety of functions in the print production process, including prepress, print buyers and specifiers, quality and process control, and press operators.

Table of Contents:

The Basics of Densitometry

How Densitometers Work

Wide-band, Narrow-band, and Bandwidth

Polarized Filters Explained

Using Densitometers

Improvements in Densitometry

Standards and Verifying Conformance to Standards

Appendix A: The Process of Using the GCA T-Ref

Appendix B: Standard Lighting

Appendix C: Standard Methodologies for Determining Densitometry Capability

Appendix D: Common Characteristics of Densitometers, Colorimeters, and Spectrophotometers