In or with ?

Correct description, according to the book,  is "The woman's work area is covered in post-it notes."

Why not using " is covered with " instead of " is covered in"  ?? Both are fine, and they are often interchanged.
But here are a few comments.
'Covered in' - Sometimes suggests more complete coverage. Sometimes suggests the coverage was less intentional, more accidental.


Isn't " covered with " is more common than" covered in" ?? That's my feeling, too.

eg I tripped and fell into a deep ditch. When I got out, I was covered in mud. My friends couldn't even recognize me.
The coverage was pretty complete. And it was the result of an accident. I didn't intend to cover myself in mud.

eg I could see John had cut his knee, because it was covered with a bandage. John decided to bandage his knee. And it did not cover his whole body, it ws probably quite a small bandage. 'Covered by' is another common form here.

Clive