Occasionally I work with clients who provide me with images they have scanned (old family photographs for instance), but they turn out to be poor quality due to being scanned at low resolution. Consequently I will need to request images that are higher in resolution. Many people don’t understand what “high resolution” is. Nor does the term dpi as in “please provide a photo that is at least 5 x 7” at 300 dpi” mean anything. And why should it?! It’s not something most of deal with day after day. So let’s explore these things.
Dpi means dots per inch. If you examine an image in a book with a magnifying glass you will see that it is made up of all kinds of tiny ink dots (on a computer screen pixels are the dots that make up images). It’s highly likely that there are 300 dots of ink per inch in that book image, for that is what has been determined essential for images to be crisp and clear for printing. The exception to this is printing on newspaper because newspaper runs more easily when inked. Therefore, higher dpi is not possible – which is why newspapers don’t have the best image quality.