Understanding DPI and why it matters
As previously mentioned, pixels form the images, and how many there are in an area creates the detail or the resolution. So, the typical way this is communicated in both the print and electronic art world is in dots per inch (DPI). This represents how many pixels are present in an area of one square inch, and quite simply, the more dots per inch, the higher the amount of detail.
Typically, if you are making a piece of art for a digital screen, the general DPI is 72, as most monitors cannot go past that. However, if you are doing print work, the minimum DPI is 300, as anything less will show fewer and fewer details.
Setting the DPI affects the file size because, obviously, the more information (in this case, DPI), the larger the file is going to be. In the following figure, simply changing the DPI of the file from 72 to 300 increased the size of the file substantially:
Figure 1.6 – The effect of DPI on file size
