Use of "sleek" as a noun

I encountered a polishing cloth that has a line which says

(This cloth) generates sleeks and scratches on the glass surface.

What is the definition of sleek in this context? I looked up in a dictionary and all it says is gloss, smooth surface, but from the context it seems sleek is associated with scratch.

"Sleek" is a term used in polishing that means:

Sleek - A polishing scratch having no visible conchoidal breaking of the edges.

Another polishing site gives a better definition:

A very fine scratch visible at only certain angles. Sleeks are found during polishing, usually being caused by impurities in the polishing compound or other contaminates. Sleeks also occur when the polishing compound dries out during a polishing session.

It is used specifically for polishing scratches.