File Formats and Image Types
Vector Image
Constructed using proportional formulas rather than pixels. EPS, AI and PDF are perfect for creating graphics that require frequent resizing. Your logo and brand graphics should have been created in this format, and you should always have a master file on hand. The real beauty of this format lies in their ability to be sized as small as a postage stamp, or large enough to fit on an 18-wheeler! DPI
EPS
Format preserves vector artwork, but the encapsulated part of the format's name gives a hint about the flexibility of the format. It's a container for artwork, and it can transport vector art, as well as raster images, or a combination of raster and vector content. As the name implies, PostScript in a bag. It may contain 2D vector graphics, bitmap images, and text.
AI
Image format most preferred by designers and the most reliable type of file format for using images in all types of projects from web to print, etc. Adobe Illustrator is the industry standard for creating artwork from scratch and therefore more than likely the program in which your logo was originally rendered. Illustrator produces vector artwork, the easiest type of file to manipulate. It can also create all of the aforementioned file types.
INDD
Indesign files that are created and saved in Adobe Indesign. Indesign is a page-layout program commonly used to create larger publications, such as newspapers, magazines and eBooks. Indesign recognizes and "links to" files from both Adobe Photoshop and Illustrator to produce content rich designs that feature advanced typography, embedded graphics, page content, formatting information and other sophisticated layout-related options.
TIF
Large raster file that does not lose quality/resolution. Most useful for photographs destined to print. This is NOT a web format, it will take forever to load.
GIF
Most common for animations on the web. They have a limited number of colors and the file size is small resulting in low resolution. These images load very quickly as opposed to formats able to preserve quality and resolution.
PSD
Native Photoshop format contains layers to make modifications easier. Raster based file.
Raster Image
Photographic images for print or online. When stretched to fill space they were not originally intended to fit, they distort resulting in blurry or unclear images. In order to retain quality, you cannot resize these images without compromising their resolution. As a result, it is important to remember to save these files at the exact dimensions needed for the application
BMP
Popular graphics file format used on Windows-based PCs. If you use a PC at work, or if you've got friends who do, you may encounter this format. Also called "line art images," images contain only black and white pixels, with no intermediate shades of gray. Great format for a signature to add to an editorial page or scan a pen and ink sketch, a this format can provide a sharp, clean image.
Takes a "picture" of an electronic document preserving the fonts, graphics and images which can be opened on any computer by anyone, anywhere. This format can also preserve vector graphics. Most often used for transporting documents in a "printed" format for download from a web site or to send a final "print-ready" document to a printer. This format can be high resolution for printing or compressed web. The best universal tool for sharing graphics and documents.
PNG
Use for web pages but not suitable for print as they are typically lower resolution. Images and graphics can be saved with a transparent background enabling you to place a sharp, web-quality image on top of a colored background without a "white box around it".
JPG
Use for web, documents such as Word or PowerPoint. However, you must pay attention to the resolution and file size in order to produce a nice looking printed product and to ensure efficient download speed for web applications.
ESP
Vector format for high-resolution graphics. Best used for logos, line-art, illustrations as it is scalable. You can resize small to large and vice versa without sacrificing resolution and quality. Native format of all logos and a copy of this file should be stored in a safe place as these files can be converted to raster but cannot go back to vector.
