The Web Browser and Screen Resolution
Web browsers display and print from the screen image at 96 DPI. Therefore, a 300 dpi JPEG or JPEG image will appear and print about 3 times larger than normal! This can be a problem with some solutions if the barcodes you are creating over the Internet require precise X dimensions (the width of the narrow bar). For example, the minimum allowable X dimension (the width of the narrow bar) of a browser barcode that uses an applet to display a barcode must be a multiple of 1/96 of an inch (about 10 mils), or about .03CM. Most ISO and AIM standards indicate that the minimum X dimension should be 10 mils for open systems (meaning compatibility with different barcode scanner brands), so this is usually not an issue.
COPIED FROM THE WWW
JIM