Flap/tape/piece of cardboard

• Flap shutter (2)

Sliding shutters (cardboard, wood, metal)

• Cardboard slide shutter
• Wooden slide shutter (1)
• Wooden slide shutter (2)
• Wooden slide shutter (3)
• Metal or cardboard slide shutter (1)
• Metal slide shutter (2)
• Metal slide shutter (3)
• Metal slide shutter (4)

Rotating/swinging shutters (cardboard, wood, metal)

• Wooden rotating shutter (1)
• Wooden rotating shutter (2)
• Wooden rotating shutter (3)

Cable release shutters (sliding or swinging, wood or metal)

• Shutter release sliding shutter
• Drawing of shutter release sliding shutter
• Cable release swinging shutter
• Internal cable release swinging shutter (1)
• Internal cable release swinging shutter (2)

Magnet shutters

• 6 x 12 cm camera with magnet shutter
• Magnetic paper holder as shutter
• Can camera with magnet shutter

Lens cap shutter

• 72 mm filter ring and lens cap

More ideas for shutters will be found in the f295 forum for construction of lensless cameras.