Possible Clues:

• Artist's stereotypical topper
• Parisian topper
• Covering for la tête
• Hat painted by Renoir
• Cap. letters from December etc.
• Bohemian's accessory
• Army Ranger's topper
• Headwear in iconic Che posters
• * 'I got this hat at a thrift store; all I had to do was clean it...'
• Artist's topper, stereotypically