A correspondent recently complained that a university quoted photographic paper sizes to him in imperial units. This reminded me of an unpleasant discovery I made some years ago.
Following an altercation with a photographic shop (over requesting sizes in cm) I once did a little research and discovered that photo paper sizes follow an international agreement which is imperial. Thus the popular 6 x 4 size actually is 153 x 102 mm (not 15 x 10 cm as I had assumed). Either way it is a stupid anomaly as it does not correspond to the A6 size, which is 148 x 105 mm. Hence, 4 prints will not fit on to an A4 sheet.
This is all presumably because of the historic dominance of the American photo industry, but you would think that Agfa, Fuji etc would have challenged it before now. Does anyone know whether the position is the same in continental Europe and elsewhere in the world?