Print reproduction involves physical/mechanical interaction between the imaging cylinder, dry/liquid toner, and the substrate. Most photographic technology prints will heavily degrade after about fifty to one hundred years after their initial printing. This allows for determining which factors, including the paper, play the most crucial role in the longevity of printed images. Other distortions may happen to images during the printing process. Printing paper or substrate is considered to be the fifth color for process color printing. Paper is considered a commodity but its properties are a long way from being standardized. The perception of color quality evaluation is strongly influenced by the properties of the paper (weight and brightness), and it is one of the most important factors in judging the color appearance of the printed material. Substrate thickness can influence the paper weight also. Color can be viewed as a science where the optical aspects of color are quantitatively analyzable and measurable. The human eye, however, perceives color more subjectively, which poses a challenge at times for the printing and image reproduction industry.
The experiment was conducted in a digital color printing workflow (DCPW) to determine the effect (impact or influence) of paper properties (thickness and brightness) on the color quality based on the statistical evaluation among nine (K = 9) different types of substrates (printing papers). Each substrate (paper) in the experiment was considered as a group, noted by letter "K" (K = 9). Paper samples with different properties (weight and brightness) were used (or selected) for the experiment. This study was focused on the measurement of color prints, printed on multiple types of substrates by using dry-toners on a digital color printing device which uses a color electrophotographic (color laser) printing technique.
Color quality was determined by carefully evaluating the printed primary colors hue. Colorimetric, denstometric, and spectrophotometric computations were used to determine the printing colors (solid CMYK) and gray color (overlap of C = 50%, M = 40%, and Y = 40%) "hue variation" (DH ) among the nine (K = 9) types of substrates with various thickness/brightness. Type of paper used for the printing will have a significant impact on the print attributes, in turn they affect the print quality/visual appearance of colors (hue). This research demonstrates the use of ANOVA to determine the influence of substrate property (thickness/weight) in the primary colors and gray color hue variation among the nine types of papers/substrates, printed in a digital color printing workflow. The findings of this study represent specific printing or testing conditions.