Related Clues:

• Emerson's 'jealous mistress'
• Some paintings
• Portraitist's medium
• Rembrandts, e.g.
• Squelches a squeak
• Word before song or glass
• Op ___
• Creative work
• Standard varieties
• Rembrandt works
• See 21-Across
• Knack
• Prints and such
• Impressionist works
• It's often left hanging