Distribution of the main grid of binary models at each metallicity over the parameter space of initial orbital periods and primary masses. Background color indicates the evolutionary stage of the primary star at the onset of mass transfer through RLOF. We differentiate between core-H burning donors (blue), H-shell burning donors (i.e., donors that experience the Hertzprung-gap phase of rapid expansion; green), as well as core-He burning donors (yellow). The initial mass ratio is q = M₂/M₁ = 0.6. Colored rectangles indicate which models from the grid are shown in figures throughout the paper (see legend).