Evolution of the bound fraction of clusters obtained in our simulations. Different colors correspond to different global SFEs (see the key). The gray lines show the impact of mass loss caused by stellar evolution alone. The vertical dotted line corresponds to t = 20 Myr.Top panel: comparison of the bound fraction evolution of isolated (dashed lines) and non-isolated (solid lines) models for M_⋆ = 6000 M_⊙ with N ≈ 10⁴ stars. Note that the isolated models are the single-mass models without stellar evolution and scaled to the same physical units as the non-isolated models (i.e., M_⋆ = 6000 M_⊙ and r_h = 1.26 pc). Bottom panel: bound fraction (instantaneous tidal mass as a fraction of initial stellar mass) evolution for non-isolated models with different initial stellar masses (see the key for the line-coding).