Two calculation forms are presented for calibrating a Kubelka-Munk (KM) translucent layer using white and black backgrounds. The equations, derived from the hyperbolic and exponential forms of the KM equations and replacing variables a and b with c=S/K and d=bc, give results identical to the usual method, but avoid near-zero divisions in the low-scattering limit. (c) 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 399-401, 2016