coating material
http://id.loc.gov/authorities/subjects/sh85027504
http://purl.obolibrary.org/obo/NCIT_C172794
https://en.wikipedia.org/wiki/Category:Coatings
https://en.wikipedia.org/wiki/Coating
https://www.wikidata.org/wiki/Q1570182
A layer of material covering the surface of a device.
coating
coating materials
surface coating
device