How Do You Figure Out Fronts and Backs of your slides?

The front of the slide has the emulsion of the film. This is the side that gets exposed with light coming through the lense and the aperture. You need to try to figure out what the fronts and backs of your slides are. 99 times out of 100, the front will be the side with the logo on it. A logo is the name of the film company that was used or the processing company such as Kodak. The back side will be pretty much blank with only a number or date on it.