
Originally Posted by
djshok
Sure thing. DPI is dots per inch, the term comes from inkjet printers that print images using actual ink dots (think of how an old comic book looks) it doesn't really affect how things look on screen so much as how they do when printed (on screen a higher DPI image will just look bigger). The higher the DPI the nicer/sharper the printed image looks, this is true with all printers. Which is why TCP has that strict 300 DPI rule for all the covers there. Standard DPI for online images that aren't meant to be printed is 72. The issue with uploading 300 DPI images to most image hosting sites is that they're really just meant for hotlinking, so by default they resize your image to 72 DPI, the problem is a 300 DPI image is much larger so what ends up happening is you lose your formatting and when you try to print the image it ends up being too large to fit on a page.
The relationship between DPI and resolution is a little awkward to imagine because computer monitors don't display in DPI, they do in pixels. So what ends up happening is a high DPI image is also high res because it is made up of more pixels. Then when you resize it to say something like 6.7" x 10.2" and print it, all that detail gets crammed into a small space making the image look nice and sharp.