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Treat the specified particles only as rigid geometric shadowing objects; no biological preparation or interpretation is needed. Their projected shapes are rounded-ended rods with straight central length $100-30=70\mathrm{nm}$ and cap radius $15\mathrm{nm}$. Normal, collimated evaporation deposits metal in the gaps between projected particle footprints, leaving isolated small islands after mask removal, rather than a metal replica of each rod.

One concrete dense parallel packing has center translationsAdjacent rounded ends then touch at triangular arrangements. The open regions are small curvilinear triangular gaps near those ends. This is a specified geometrical packing for the sketch; the words close-packed do not uniquely prescribe the domain orientation or registry of all real sheets.

Particle size and shape distributions change the gap size and spacing. Misorientation, missing particles, boundaries between ordered domains, overlaps, incomplete coverage and drying-induced cracks interrupt long-range order. Substrate roughness and uneven adhesion distort the arrangement. A finite source angle produces deposition shadowing and penumbra; surface diffusion, island nucleation and increasing film thickness can broaden or merge deposited regions. These are generic geometry and materials effects, not assumptions about a biological assembly mechanism.

Zero step coverage means that a sidewall or hidden surface receives essentially no film even though a horizontal reference surface is coated. Deposition shadowing occurs when an upper edge intercepts trajectories that would otherwise reach a lower region. A directional high-vacuum evaporant flux can therefore coat a feature top while leaving vertical or reentrant walls uncoated.

Sputtering generally releases material from an extended target with a broad angular distribution; gas collisions can further redistribute arrival directions. More oblique trajectories can reach sidewalls, so the extreme zero-coverage behavior of an ideal collimated evaporant beam is reduced.

The absolute claim that these effects never occur in sputtering is too strong. Low-pressure directional sputtering and high-aspect-ratio or reentrant features can still exhibit shadowing and poor coverage. Broader incidence improves access; it does not make a physical deposition process universally conformal.