Possible Clues:

• Mar or spoil the appearance of
• Give bad marks
• Vandalize, in a way
• Mar, spoil the appearance of
• Deliberately spoil the appearance of something
• Scrawl graffiti on, e.g.
• Fed up with expert's damage
• Spoil the surface of as with graffiti
• Mar the surface of
• Cover with graffiti, e.g.