Common Graphic Formats
Nothing in the world of desktop publishing is ever as simple as it should be.
Take graphic formats. At first glance,the question of which graphic file format is best would seem like a simple one. The answer, however, is anything but straight forward. The format you use is entirely dependent on what you are using the graphic for, the program you are using the graphic in, and where your finished document is going to end up.
With that in mind, here is a basic rundown on some of the common graphic file formats. Keep in mind that there are literally hundreds of formats out there, some of them harking back to the days of the Amiga, so this article only covers the most common.
At the top of the list is the JPEG format, a graphic compression scheme that was developed as a means of creating images for use on the web. The JPEG format is now very common, both because of its widespread use on the Internet and because most digital cameras convert images to this format. While in the past printers and film houses discouraged the use of JPEGs (in part because the format results in some data loss when it compresses an image), this graphic type has gained such wide acceptance, and has such versatility, that it is now used by many desktop publishers for print work.
Next up is TIFF. This used to be the workhorse of the graphic format world. Standing for Tagged Image File Format, TIFF files are bitmapped images (that is, each pixel is represented by a piece of data). TIFF files can be used on almost every software and operating system and are good for high quality images. On the downside, they can be very large and unwieldy, especially when they are high resolution CMYK files.
An EPS (Encapsulated PostScript file) is a common vector type file format which is good for high resolution art, including logos that need to be blown up. A logo in EPS format can be resized more readily than its bitmap cousin because, instead of using pixels to represent data, EPS files use complex mathematical formulas to represent a graphic.
GIF, which stands for Graphics Interchange Format, is a graphics format designed for the Internet. It is great for certain uses on the web (like logos or clip art), in part because GIFs are small and as a result download quickly. However, the GIF format utilizes only 256 colors or 256 shades of grey, making it a less than ideal format for print work.
BMP is a bitmap file format, which was designed originally for Microsoft Windows and OS/2 operating systems. While it is a very common format, many high end print houses and designers traditionally shied away from it because BMP was originally designed for the Windows environment, and sometimes didn’t cross over well into the Mac-centric world of high end desktop publishing. Nowadays this is not as big of an issue, but many printers and film houses still encourage conversion of BMP files to TIFFs, just to be on the safe side. The Macintosh cousin of the BMP is the PICT.
A PSD is a native Photoshop file. It offers a wide variety of option when opened up in Photoshop (not the least of which is the ability to manipulate various layers), but cannot be used in a page layout program. It must be converted to another format (like TIFF, EPS, or JPEG) before being placed in a program like InDesign or Quark.
A PDF, which stands for Portable Document Format (and was created by Adobe) is theoretically not a graphic format, but rather a document format. However, PDFs can now be placed as graphics in some page layout programs, which is why we mention them quickly here.
A word of advice on converting files from one format to another. It must be done in an image editing program. As basic as that advice may seem, more than one beginning desktop publisher has thought that renaming a .bmp file with a .tif extension (without otherwise doing anything to the file) actually converts the graphic to the new format. It does not.