Related Clues:

• Inky smear
• Blemish
• Bad mark
• Key blunder
• Rorschach ink mark
• Part of a Rorschach test
• Printing goof
• Tit for tat, maybe?
• There's one et 24-Across
• Black mark
• Keyboard slip
• Tears for Fears, e.g.
• Dry with absorbent paper
• Rorschach mark
• Proofreader's concern