In this study, we present theoretical calculations and experimental verification regarding the spectral distribution of emissivity constant, which plays an important role in the image formation in the hyperspectral imaging systems. In this study, the theoretical formulations regarding the spectral emissivity calculations for metal plates are provided. These metal plates are produced and their emissivity spectra are measured and compared with theoretical results. The experimental and theoretical results in this study show a good agreement. The emissivity spectrum calculations and measurement using alternative techniques is important for the development and improvement of hyperspectral imaging techniques.