Which format to use?
EPS–If you are using more advanced graphics software (e.g., Adobe Illustrator, Freehand) or desktop publishing programs (e.g., QuarkXPress, InDesign) you will want to use the logos available in the EPS format. The .eps images provided here are vector-based, which means that they are resolution independent—based on objects, not pixels. Vector-based EPS graphics will print better than the bitmapped TIFF, so when providing the logo for publishing purposes use EPS. EPS files are zipped to avoid compatibility problems. This file type works best with programs such as In Design or Quark used for printed materials.
JPG–JPG is the most common format used for storing and transmitting photographs on the web. It is not as well suited for line drawings and other textual or iconic graphics because its compression method performs badly on these types of images. The JPG file is wonderfully small, often compressed by 90%, or to only 1/10 of the size of the original data, which is very good when modems are involved. However, this fantastic compression efficiency comes with a high price. JPG uses “lossy compression” (lossy meaning “with losses”). Lossy means that some image quality is lost when the JPG data is compressed and saved, and this quality can never be recovered. This file type works well for web and email applications.
PNG–Portable Network Graphics (PNG) is a bitmapped image format that employs “lossless” data compression. PNG was created to improve upon and replace the GIF format and was designed for transferring images on the internet; however, older browsers may not fully support it. A PNG is similar to a JPG with a few exceptions, the most important being it can be placed on a color background other than white. It supports smooth transparency for any background color. PNG files should be used in Word and PowerPoint documents when the background color is not white. This file type works well with Power Point presentations used across Mac to PC or PC to Mac platforms.
GIF–GIFs are compressed images used on the web. GIFs are based on indexed colors, which is a palette of at most 256 colors. This helps greatly reduce their file size. These compressed image files can be quickly transmitted over a network or the internet, which is why you often see them on web pages. GIF files are great for small icons and animated images, but they lack the color range to be used for high-quality photos. This file type works well for web applications. This format has a transparent background, and works well with a colored background.