The 3:2 format is a standard format in which images are printed.
This format is used to print mainly wide panoramas
This format is self-explanatory, the edges are all the same length and thus form a square
In some images it is not possible to determine a unique format due to e.g. special cropping*.
*If an image meets these criteria, it is advisable to consult with me or simply select the long edge under the "Special" format settings. In my case I offer 50, 75, 90 and 100cm to order. The shorter edge then adapts to the desired length and thus the whole image can be printed without loss.