Characterization of Angle Dependent Color Travel of Printed Multi-Color Effect Pigment on Different Color Substrates
Color-travel pigments, which exhibit much more extensive color change as well provide angle-dependent optical effect can be used in many industrial products. In present paper the multi-color effect pigment printed on three different foils with different background color (black, silver and transparent) was investigated. The pigment was based on synthetically produced transparent silicon dioxide platelets coated with titanium dioxide. CIEL*a*b* values and reflection of prints were measured by multi-angle spectrophotometer at constant illumination at an angle of 45o and different viewing angles (-15o, 15°, 25o, 45o, 75o and 110o) were used. The measurements of printed multi-color pigment showed that CIEL*a*b* color coordinates varied to great extents, depending on detection angles as well on color of the printing substrate. The study revealed that pigmnet printed on black background obtained significant change in color. The study has also shown that when viewing angle increases, the reflection curves decreases.
Use of effect pigments for quality enhancement of offset printed specialty papers
Nowadays, effect pigments are widely used in many printing industries. The colorful effects produced by light scattering of these types of pigments add an additional value to the prints and enhances the overall quality of color appearance. The aim of this study was to investigate the quality enhancement of printed specialty papers with various effect pigments in combination with offset inks. Four different effect pigments were used (one luster pigment-EP1, two interference pigments-EP2, EP3, and one multicolor pigment-EP4) as well as two types of paper substrates (film synthetic paper and wood-free paper). The effect pigments were overprinted on dried CMYK offset prints on both paper substrates. The following analysis were performed: scanning electron microscopy analysis of effect pigment particles, contact angles of papers and offset prints, Fourier transform infrared spectrocopy (FTIR), principal components analysis (principal components analysis (PCA)), and flop index analysis of overprinted effect pigments, and paper and print gloss. The results of the experiment indicate that effect pigments behaved differently on different printing substrates. From the FTIR and PCA, it was found that the different composition of effect pigments differently influence the behavior of these particles on the final prints. Effect pigments overprinted on offset CMYK inks on both paper substrates enhance print gloss, except interference pigment EP2 on film synthetic paper. It was also found that the ink color has the most pronounced influence on flop index, followed by the papertype and the type of effect pigment. Higher flop index was obtained at wood-free paper, especially by overprinted pigment EP2. © 2012 Wiley Periodicals, Inc. Col Res Appl, 38, 168–176, 2013.
Educating the Educators: Rethinking Subject Matter and Methods
gate? In addition to general requirements in their professional education such as psychological and social foundations and student teaching, what specifically do social studies teachers need to know and be able to do? What, in particular, do they need to study in the subject matters of the social sciences (defined here, for purposes of brevity, to include history and geography), and what should they learn about its effective direction to desired results, that is, method? Usually answers to the first question require reference to the liberal arts component of teacher education and the second to methods in the professional education component. As we shall see, this separation of subject matter and method in the education of social studies teachers, although conventional, poses problems.