What is D.P.I. and how it will affect your printed images?
DPI, or “Dots per Inch” is the measurement used within the printing and graphics design industry to determine how sharp and defined an image is. Web graphics and online photos are normally created at 72 DPI (dots per inch). This low resolution is great for the web because the images look excellent on a computer monitor and the file sizes are very small which helps web pages load faster. However, when designing graphics for commercial printing purposes, your images should be 300 DPI or better.
When an image is printed, it is really a collection of tiny dots of colors that make up the colors of the image. This is similar to how digital images are displayed in pixels. If an image on the web has a low PPI (Pixels per Inch) it will become grainy if you try to make it too large.
The example to the right demonstrates the difference in image quality between 300 DPI and 72 DPI. The image with only 72 DPI is noticeably more distorted. When an image is expanded to actual size, it exposes the dots, making the image rough and grainy. This is similar to digital images using pixels. The more dots/pixels the image contains, the sharper the image will print. As a result, printing will look blurry if a 72dpi image is used as compared to using a 300dpi high res image.