Ratios of the SCO-RCG Rosseland means and those of OP or OPAL in the (T, N_e) plane. κ_R, SR is the RMO from the new data and κ_{R, OP, OPAL} that of the comparison dataset. Top panel: comparison with OP. The SCO-RCG RMOs can be up to six times larger than those of OP in a narrow band in the Z-bump, around log T = 5.3. Bottom panel: same plot with OPAL. The OPAL temperature step is larger for log T > 6. The area in which the SCO-RCG RMOs are higher than those of OPAL is larger than for OP.