The theory behind the use of layers of radar absorbing materials or other dielectric materials is identical to the theory of optical reflection and transmission through layered media. This report is intended to be of use to students studying the application of layered media to a radar cross-section reduction problem. In this report, we survey several established optics and electromagnetics texts. We critique them and attempt to reconcile differences. We arrive at a single consistent theory which fully considers lossy materials. Layers are depicted as matrices which can be multiplied to combine the effects of several adjacent layers. We can then find the transmissivity and reflectivity of the entire multiple-layer structure. This theory is implemented in the MATLAB language in a user-friendly format.