Pearlescent tape and similar decorative films exhibit color changes based on the angle of observation due to the principle of wave interference, similar to professional diffraction gratings and dichroic mirrors. While both types of materials utilize light interference, they operate on different physical principles and have distinct properties. Pearlescent tapes are often made from layers of mica coated with titanium dioxide, creating iridescent effects, while professional gratings can provide precise measurements and are typically more expensive. The discussion also highlights the affordability of decorative alternatives for educational purposes, suggesting that these tapes can serve as substitutes for more costly optical equipment. Overall, the exploration of these materials reveals their practical applications in decoration and the science behind their optical effects.