Evaluation of Light Measurement Instruments

The International Standards Organization (ISO) defines standards to ensure that viewing conditions are consistent when evaluating printed samples through ISO 3665 (2009), Graphic technology and photography – viewing conditions. The need for this standard stems from the necessity for human visual assessment as the key arbiter of the quality of complex images, and the tendency for various lighting conditions to shift the appearance of a color, specifically in relation to other adjacent colors. Among the conditions specified by ISO 3665 (2009) are Correlated Color Temperature (CCT) and Color Rendering Index (CRI). CRI is expressed as CRI Ra, with Ra representing the international standard for CRI as defined by CIE 13.3-1995. Both CCT and CRI Ra are quantifiable by a range of instruments, including traceable Spectroradiometers specifically designed for the purpose, general-use Spectrophotometers that can read CCT and CRI Ra, and handheld instruments designed for photographic applications that measure CCT. The present study seeks to compare readings from a traceable Spectroradiometer with those from various other meters across a range of seven viewing booths, some of which are known to be out of specification. The goal is to ascertain how much variance can be expected when using these varied meters when compared to a traceable benchmark instrument

Color Studies Curriculum: Re-Envisioning Josef Albers’ Interaction of Color in the Digital Age

The present study considers the possibility of using digital technologies to improve established color studies teaching methods, which are largely based on visual evaluation. Experiments utilized in this study are based on work outlined in Josef Albers’ Interaction of Color (2009). Albers, a famous artist and art educator, has made significant contributions to the field of color studies. In this paper, the researchers conduct two experiments to assess the efficacy of two different approaches to Albers’ traditional methods of color studies pedagogy by seeking to replicate examples from Interaction of Color. In the first approach, modern ICC-profile-based color management tools are used with an inkjet printer to determine if two illustrations featured in Interaction of Color can be faithfully reproduced. In the second approach, color measurement technologies are used to ascertain if colorimetry can be useful in selecting optimal paper samples from a set of Color-aid papers, a collection of 314 screen printed papers especially utilized by students studying color in curricula prescribed by Albers. The illustrations selected from Interaction of Color for the study are based on the visual phenomena described as ‘Two Colors as One’ and ‘One Color as Two’; these phenomena are otherwise termed ‘simultaneous contrast’ (e.g.: Long, 2015; Fairchild, 2005, Berns, 2000). The results of this study reveal limitations of these digital methods as compared to visual evaluation when replicating the visual effects of illustrations from Interaction of Color and provide insights that may enhance future curricula in color study fields

Evaluation of TAPPI Brightness versus Other Brightness Indices

The primary goal of the present research it to establish the variance that can be expected when measuring TAPPI brightness as a traceable metric with a laboratory-grade meter compared to brightness indices measured by production-grade spectrophotometers. It is also recognized that the variance between the analyzed metrics may differ based on the type of paper measured. Therefore, this research also aims to examine the brightness across several types of papers commonly used in the printing and packaging industry. In addition, an important property of many paper substrates known as optical brightness agents (OBAs) is analyzed with a goal of ascertaining its influence on brightness readings among the evaluated instruments and metrics. OBAs are commonly used chemical materials in paper pulp, which can enhance the brightening effect on the appearance of the material. After data collection and analysis, it is concluded that the brightness indices from the production-grade instruments used in this study result in higher readings than TAPPI brightness readings. The level of OBAs in the paper is also found to influence paper brightness readings