Instant Film Sizes

Here is a refrence photo to show the size differences between these three ways you can go for instant film photography.

3.25x4.25 pack film (Fuji and Polaroid),
4x5 pack film (Fuji) and single sheet film (Polaroid, not pictured),
8x10 single sheet film (Polaroid). The larger format films require separate film holders, and the 8x10 film a separate processor, as well.