Unlike photographic prints, slides must be put into slide mounts in order to be of any use. The process of mounting slides ranges from a simple pair of scissors to slide-mounting machines, costing tens of thousands of dollars.

Whenever handling slides, you should wear cotton gloves to avoid fingerprints on the image area. If finger-prints do get on the slides, a cotton ball moistened with film cleaner should be used to remove them.

Slides can be mounted in either cardboard or plastic slide mounts. When using cardboard slide mounts, you must heat them so the slide adheres to the mount. Navy imaging facilities use plastic slide mounts. The slides can be placed in plastic slide mounts manually or by machine.

To mount slides manually, you must cut the roll into individual frames. Normally, this is done on a light table so the edges of the frame can be seen clearly. To mount a slide, you simply slide the frame into an open slit on the edge of the slide mount. On one side of the plastic slide mount is the lettering, THIS SIDE TOWARDS SCREEN. The lettering appears along the side of the open slit. The slide is mounted properly when the emulsion side of the film faces the lettering, and the slide is straight. No light should pass between the edges of the film edges and the mount.

When projected slides appear correctly on the screen, they are placed in the projector (or slide tray) upside down and backwards, as viewed from the operator's position. An operator's dot is often placed on the slide mount to aid in organizing the slides in the tray. When the slide is viewed with the emulsion side towards you and the image is upside down, the operator's dot is marked on the upper right-hand comer of the slide mount. The slides are placed into the slide tray correctly when the operator's dot can be seen facing the outside of the tray.