Related Clues:

• Do a certain cartoonist's job
• Pad content
• Newspaper need
• Marine defense, perhaps
• Penman's paint?
• Lithography need
• Printer's buy
• Writing material
• It may be invisible
• Sign, per Variety
• Pen partner
• Tattoo parlor expense
• Tattoo, so to speak
• Well liquid
• 36-Down filler