Anchored by a metal framework and covered with waterproof sheeting and absorbent material, the 'walls' support a dense layer of uniform greenery.

This species builds open burrows, lined with a dense layer of silk.

The leaflets are covered with a dense layer of silver hairs, angled forward at 70-80.

Alternatively, planetesimals can form in a very dense layer of dust grains that undergoes a collective gravitational instability in the mid-plane of a protoplanetary disk.

The combined mineral load of the ocean reacts with corroding metals and surrounding sediments to form a dense layer around the metal.