The solution depletion method of measuring adsorption from binary-protein solution is complicated by the fact that there are two broad categories of adsorption competition falling into 5 sep- arate cases that can be studied [14]. The first category consists of a single experimental situation termed Case 1 in which total binary- mixture concentration is insufficient to saturate the adsorbent surface. The second category consists of four different experimen- tal situations termed Cases 2–5 in which the total-mixed-solution concentration is sufficient to saturate the adsorbent surface that can be obtained by combining i, j proteins at different concentra- tions relative to that required to saturate the adsorbent surface area with either pure i or pure j. Case 5 differed from surface-saturating Cases 2–4 in that both competing proteins were mixed at solution concentrations well in excess of the amount needed to saturate available adsorbent. At least one of the competing proteins was at under-saturating solution concentration in Cases 2–4. We have extensively tested each of these conditions with proteins listed in Section 2 [14] but disclose results herein for Case 5 for i = FII and j = Fib which has not been illustrated previously.