Quote: In which case, your picture is 1800 x 1800 pixels = 3,240,000 pixels; at a print resolution of 300ppi, that gives a print area of 10,800 square inches (eg a print something like 108 x 100 inches).
300dpi, 300ppi - all the same.
But a picture of 1800x1800 pixels will not give you an image of 108x100 inches! That would be 32400x30000 pixels at 300 dpi!
1800x1800 pixels should give you a 6x6 inch photo.
Not quite sure why 'Print Preview' is giving you a bigger picture, unless you've got Scale to fit media selected on the Print Preview screen. That would stretch the photo to fit the page. This is the only thing I think of that would cause this particular problem.