<p>We developed a
mathematical process to quantify the apparent darkness of solutions containing
melanin-like materials. The visible portion of their UV-Vis spectra is model
using an exponential equation. Linear regression analysis provides the
constants that define this exponential equation. Using these constants, the
exponential equation is integrated between 400nm to 900nm to obtain the
area-under-the-curve (AUC) of the visible portion of the UV-Vis spectra. This
process was applied to data collected from various melanin-like materials
discussed in earlier reports. By comparing the AUC values of different samples
one can readily compare the “darkness” of melanins and evaluate the impact varying
reaction conditions may have on this physical property. We revisited the
results of earlier reports and discuss additional points related to the UV-protective
properties attributed to melanins.</p>