What kind of file do you need?
You are working with a designer on a website. You have a logo and some photographs you would like them to use. You say you will send them the electronic files. It seems simple enough, but in the ensuing conversation about file formats it becomes much more complicated, and maybe a bit frustrating.
This article will help you understand just enough about graphic file formats to eliminate the frustration.
First, an introductory note. Graphic images are stored either as “bitmaps” or “vector graphics.” These aren't file formats, but rather types of formats. Bitmapped images are composed of a pattern of small squares (pixels). If you enlarge the image, the squares get larger, and the image breaks up. This is good for pop-art-like special effects, but not for more conventional image use. Vector graphics use geometrical formulas to represent images and are more flexible than bit maps because they can be resized and still look just as crisp. Vector graphics are also smaller files than bitmaps.
Here are the major file types used in graphic production:
EPS Encapsulated PostScript
Extension: .eps
Type: bitmap or vector
Used for: Logos and illustrations
This file type is perfect for logos since you can change image size without worrying about the image becoming ragged, distorted, or fuzzy. Most logos are done in a program such as Adobe Illustrator and saved as an EPS file. EPS files can contain both vector and bitmap graphics and are supported by most graphic and page-layout programs.
JPEG (“jay-peg”) Joint Photographic Expert Group
Extension: .jpeg
Type: bitmap
Used for: Photographs on a website JPEG files use a compression method that can significantly reduce the file size of photographs and other continuous-tone images. JPEGs can not be made transparent, which means they are not suitable for all website uses.
GIF (“giff” or ”jiff”) Graphics Interchange Format
Extension: .gif
Type: bitmap
Used for: Flat color graphics or logos for a website.
The GIF format is particularly suitable for line-art and images which contain large areas of the same color. The GIF format does not store photographic and continuous tone images as well as JPEG files. GIFs can be used on websites in situations where JPEGs are not suitable. They can also be animated.
PDF Portable Document Format
Extension: .pdf
Used for: Reviewing, sharing and printing documents; placing downloadable files on a website. Properly prepared high-resolution PDFs can be used for commercial reproduction.
The PDF format preserves the fonts, images, graphics, and formatting of an original application file, and allows a user without the original application to look at the output. Because PDFs are typically much smaller than the original document, they are especially useful for reviewing multi-page documents.
TIFF Tagged Image Format File
Extension: .tif
Type: bitmap
Used for: High-resolution photographs for printed material.
The TIFF format is a widely supported file type that can store all the detail needed to produce high-quality photographic images for hard copy. Files can be quite large, and so are not suitable for web use. TIFF graphics can be black and white, gray-scaled, or color, and they can be saved at any level of resolution.