The 4x6 photo size became popular for a few reasons. Firstly, it was an easy and affordable size to produce during the early days of photography. Printing photos at this size was relatively simple and didn't require large equipment or specialized paper.
Secondly, the 4x6 size is a good compromise between size and cost. It's small enough to be easily stored and shared, but large enough to clearly display the subject of the photo. Additionally, printing photos at 4x6 size is economical because it maximizes the number of prints that can be produced from a standard sheet of photo paper.
Finally, the 4x6 size became a standard for printing photos due to its compatibility with existing photo albums, frames, and other photo display methods. This made it easy for people to organize and display their photos in a consistent and uniform way.
Overall, the 4x6 photo size's popularity can be attributed to its affordability, practicality, and compatibility with existing photo display methods.
Because of its popularity you can find a wide selection of 4x6 photo folders at Pictura Supply