Okay. This is something that I really need to talk about. Although this is mainly geared towards people breaking into the comics industry, the concept is also very important for anybody interested in illustrating or working with digital images. If you are that type of person, listen up. We’re gonna do some learnin’!
All right. So there are two subjects that are really rather inter-related, and these are image resolution and antialiasing.
Image Resolution vs. Image Size.
A lot of people get these two things mixed up, and a lot of software doesn’t help with this either. Image size is not always the same thing as resolution.
Image Size – The physical dimensions of an image, particularly when the image will be printed. This is often defined in terms of inches or centimeters. This can be anything you want, as long as you know it is set to the maximum size you will want to print your image at. Unless you have no other option, do not determine your image in terms of pixels unless you are specifically creating a graphic for use on the web or in video that will not be used in print.
Image Resolution – The resolution of an image is related to the pixel density, or pixel count, given in a particular image. This is traditionally defined in terms of DPI, or Dots Per Inch (The metric equivalent being Dots Per Centimeter or DPCM). DPI is defined in terms of print or video resolution in which the number represents the number of dots that can be displayed in an inch. The higher the DPI, the more detail is stored in an image. This resolution also comes into play when you are scanning in an image.
Update: As one of my readers commented below, the proper term for resolution is actually PPI, or Pixels Per Inch. But this is typically used interchangeably with DPI.