The following is a list of common file formats and their appropriate uses.
JPEG (Joint Photographic Experts Group) Primarily a format for optimized photographs to be used on the internet. Due to the compression features of a JPEG, image quality is reduced every time that it is saved. In order to retain the quality of the original image for reproduction, native JPEG files should never be saved a second time as a JPEG. JPEG files are acceptable for commercial reproduction if they are a minimum of 300 dpi and the original JPEG file.
GIF (Graphics Interchange Format) A web-based graphics file that supports 256 colors and background transparency. When files are saved in the GIF format they are automatically optimized at low (web) resolution, usually 60-72 dpi, and the colors are reduced. GIF formats are not acceptable for commercial reproduction printing.
TIFF (Tagged Image File Format) The standard raster file format for graphic images such as photos. TIFF formats support full color and gray scale. TIFF formats do not compress when saved and thus do not reduce in quality. TIFF formats can be scaled to some extent before losing quality. TIFF images are either cmyk or gray scale color mode and are the preferred format for photo reproduction providing that the resolution is a minimum of 300 dpi.
EPS (Encapsulated Post Script) The standard vector file format for graphic elements such as text, line drawings, logos, clip art, etc. Vector EPS formats are not resolution dependent, they are comprised of mathematical points, lines, and shapes and can be scaled to any size. Raster files can be saved in EPS format as well, so it is important to note whether a particular file is a “vector eps” or a “raster eps”. EPS formats are acceptable for commercial reproduction. Raster EPS formats must be a minimum of 300 dpi.
PDF (Portable Document Format) A standard format for the transfer of proofs via internet and accessible on every computer platform. PDF files allow you the option to embed fonts, thus eliminating copyright violations as they are not distributed for general use. PDF files are acceptable for commercial reproduction if they are correctly color separated, accurate in size, fonts are embedded and the files do not need any further corrections or additions.
BMP (Bitmap) A resolution-dependent raster graphic comprised of points or dots. BMP files are acceptable for commercial reproduction, but due to their make-up they must be very high resolution, a minimum of 800 dpi, and properly separated by color.
PNG (Portable Network Graphics) A bitmapped graphics format originally created to replace .gif files for photo internet and web applications. PNG formats can handle greater color depth. PNG files are acceptable for commercial reproduction at a minimum of 300 dpi and properly separated by color.