What's the noun for plaque? Here's the word you're looking for.
plaque
Any flat, thin piece of metal, clay, ivory, or the like, used for ornament, or for painting pictures upon, as a slab, plate, dish, or the like, hung upon a wall; also, a smaller decoration worn on the person, as a brooch.
A piece of flat metal with a writing on it, attached to a building to remind people of a person or an event.
“Carotid artery stenosis is characterized by atherosclerotic changes, plaquing, ulcerations, and a progressive narrowing of the carotid vessels.”
“We examined the efficiency of plaquing and phage virion integrity, as determined by in vitro assembly, immunological detection and electron microscopy.”