We see acronyms such as PNG, BMP, GIF and JPEG every day – buying stock images, creating our own files and preflighting the files of others.

But there is still some confusion out there on what they mean (No, PNG is not the Stock Exchange symbol for the company that makes golf clubs) and which image formats are appropriate for print production.

Claudia McCue, author of Real World Print Production, gets down to the nitty-gritty to give readers not only the how-tos of getting jobs to print as expected, but equally important, the how-NOT-tos!

With this short and sweet list, you won’t be wasting any more time redoing your work (or someone else’s) …

Some image formats are intended primarily for onscreen and Web use. Portable Network Graphics (PNG) images can contain RGB and indexed color, as well as transparency. While PNG can be high resolution, it has no support for CMYK color space.

The Windows format BMP (an abbreviation for bitmap) supports color depths from one-bit (black and white, with no shades of gray) to 32-bit (millions of colors), but lacks support for CMYK. BMP is not appropriate for print.

Graphics Interchange Format (GIF) is appropriate only for Web use because of its inherently low resolution and an indexed color palette limited to a maximum of 256 colors. Don’t use GIF for print.

JPEG (Joint Photographic Experts Group), named after the committee that created it, has an unsavory reputation in graphic arts. Just whisper “jay-peg,” and watch prepress operators cringe. It is a lossy compression scheme, meaning that it discards information to make a smaller digital file.

Assuming an image has adequate resolution, a very slight amount of initial JPEG compression doesn’t noticeably impair image quality, but aggressive compression introduces ugly rectangular artifacts, especially in detailed areas.

Excerpted from Real World Print Production by Claudia McCue. Copyright © 2007. Used with permission of Pearson Education, Inc. and Peachpit Press.

More details on the book can be found at www.peachpit.com/title/032141081.

9/26/07