A 600 pixel square image set to 300PPI will print a 2 inch square image (600 pixels divided by 300
printed pixels per inch).
Not exact matches
At 326
pixels per inch, the iPhone 4 and its successor, the 4S, provide text that looks like it was
printed on paper and display photos and videos in high definition.
However, dpi is dots
per inch, a measurement for
print only; ppi is
pixels per inch, a measurement for screens only.
PPI is information set in your image editor telling the printer how many of those
pixels of the image to
print per inch of
printed paper.
So an image input to the printer providing information that it should be
printed at 300
pixels per inch will look better the higher the dots
per inch setting because the printer will lay down more ink in each
inch of
printing the higher the setting.