File Formats and Resolution
Tagged Image File Format .tiff, .tif (lossless data compression) Lossless file format, preferred format for print, can be formatted for PC or Macintosh Operating system
Photoshop Document .psd (lossless data compression) Lossless file format, includes all layers, channels, paths, etc... most of this information is not needed for print reproduction. This format can now be used as a linked file by most prep houses allowing for transparent backgrounds and masks to be printed directly a Photoshop document.
Joint Photographic Experts Group .jpeg, .jpg (lossy data compression) Used primarily for web images.The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality.JPEG typically achieves 10:1 compression with little perceptible loss in image quality.
Graphics Interchange Format .gif (lossy data compression) Used primarily for web images. The format supports up to 8 bits per pixel thus allowing a single image to reference a palette of up to 256 distinct colors. It also supports animations and allows a separate palette of 256 colors for each frame. The color limitation makes the this format unsuitable for reproducing color photographs and other images with continuous color, but it is wellsuited for simpler images such as graphics or logos with solid areas of color.
Portable Network Graphics .png (lossless data compression) Used primarily for web images. PNG was created to improve upon and replace GIF (Graphics Interchange Format). Was designed for transferring images on the Internet, not for print graphics, and therefore does not support nonRGB color spaces such as CMYK.
Portable Document Format .pdf (lossy data compression) The standard for document exchange. The file format created by Adobe Systems in 1993 is used for representing twodimensional documents in a manner independent of the application software, hardware, and operating system.
Encapsulated PostScript .eps
This format is a common format for vector graphics such like those created by Adobe Illustrator
Lossy Compression- Discards data even at the expense of visual the quality being affected to make file sizes smaller.
Lossless Compression- Keeps all data even at the expense of the size of the file being very large.
Cross Platform Refers to applications, formats, devices that work on different computer operating systems. (Macintosh or Windows)
.jpeg, .gif, .png, - the most common formats for the web
72ppi (pixels per inch) – most common resolution for all files for web or images to be displayed on screen.
300ppi (pixels per inch) – preferred resolution for all files for color printing. (By a professional printer or publisher)