Filmstrips are a form of instructional multimedia that display a series of images with or without narration. They consist of a long strip of plastic film coated with light-sensitive emulsion containing silver halide crystals. Traditionally, filmstrips are 35mm wide and contain 20-50 frames to convey lessons. They are used with a filmstrip projector to display images on a screen. Filmstrips provide a convenient way to make classroom teaching interesting through sequenced visuals but require a dark room and electricity to project. They have advantages of being reusable and easy to store, but pictures cannot be reordered and equipment can be costly. Proper care involves rolling, labeling, and storing filmstrips away from heat and moisture.