Co-axial, confocal, and constant-depth mantled spheroidal particle L_i factors for an a axis to mantle depth ratio a/d ≃ 3. The solid lines show the behaviour for the cores and core+mantle for the co-axial case. The short (long) dashed line show the cores+mantle L_i factors for the confocal (constant-depth) case. The L₁ factors decrease with increasing a/b, while those for L₂ and L₃ increase.