Both packs offer 3 film rolls but there are 2 main differences to consider when choosing a pack.
1. The inclusion of a B&W film in the pack
The Classic Film Pack offers 2 Color film rolls and 1 Black and White one, whereas the Sunbath Film Pack only offers color ones.
2. The development process of the film
C-41 film development is a widely adopted and popular process for developing color-negative films nowadays. With most commercial labs and even some local camera stores devoting at least one machine to this development process, finding a place to get the rolls from the Classic Film Pack developed is fairly easy.
ECN-2 film on the other hand requires a specific development process that differs from the more common C-41 one and that is only available in select laboratories. Because it requires precise temperature control, precise timing, and expertise in handling the film, finding labs that offer ECN-2 film processing can be challenging. Although ECN-2 has been getting more and more traction lately, only a limited number of specialized labs are equipped to handle this unique development process. Rest assured though, if you pick the Sunbath Film Pack, you can directly send your rolls back to Sunbath or click here for a list of labs around the world that process ECN-2 film.