Using a long metal icing spatula, cover the layer generously with frosting.

NPR: Recipe: Devil's Food White-Out Cake

The result is that any coating, such as an antibacterial layer, would be "self-repairing" after small amounts of damage, as the molecular chains just below the damaged layer re-cover the surface.

BBC: Coating heals itself after damage

They used a series of patterned masks to cover different areas of the wafer while each layer of precursor was sprayed on to it.

ECONOMIST: Combinatorial chemistry