Fraction of primaries that become hot stripped stars as a result of a mass transfer interaction, estimated based on the results from binary models as well as the assumed distributions for initial masses and orbital periods (see text). At Solar metallicity, any primary in an interacting binary eventually becomes a hot stripped star (the remaining 20%−30% are in wide noninteracting systems). At LMC and SMC metallicities, post-MS donors with masses above ≳17 − 20 M_⊙ become only partially rather than fully stripped in mass transfer, leading to a predicted decrease in the efficiency of formation of stripped stars from low-Z interacting binaries.