How to repair nick in back cover coating (Pixel 4)

I scratched/nicked the black (graphite adhesive) layer on inside of the back cover of a Pixel 4. Is there anything that I can use to cover or seal the nick (like a sealant, paint, or film) to reseal the nick? Does it need to be repaired

(The scratch looks as if I made a fine cut with an x-acto knife along/near the edge of the cover; it looks like the edge of the front cover cut it, when I temporarily re-assembled the phone [without the adhesive]).

A general photo of the inside of back cover (Pixel 4) is shown here: https://guide-images.cdn.ifixit.com/igi/...

A photo of the black graphite adhesive layer is shown here: https://guide-images.cdn.ifixit.com/igi/...