Maps of log₁₀(u/u_B, 0)(x, y) for magnetic energy density, u_B = B²/8π (upper panels), and plasma energy density, u_pl = ⟨γ⟩nmc² (middle panels), for relaxed monster plasmoids at the end of each simulation. In the lower panels, we compare 1D energy density profiles of (u/u_B, 0)(x, y₀) measured along the strip indicated in the above maps by the dashed grey lines. A common colour scale for all maps is referenced along the left axes in the lower panels. Here, we present the effect of a guide field for σ₀ = 10 and L/ρ₀ = 1800. From the left, the columns show simulations: (1) L1800_σ10, (2) L1800_σ10_Bg05, and (3) L1800_σ10_Bg1.