Path: utzoo!attcan!uunet!intercon!news From: amanda@mermaid.intercon.com (Amanda Walker) Newsgroups: comp.lang.postscript Subject: Re: Printing Barcodes Message-ID: <266FCFFF.636C@intercon.com> Date: 8 Jun 90 16:19:10 GMT References: <9208@teda.UUCP> <1004@io.tegra.COM> <1303@chinacat.Unicom.COM> <32107@sparkyfs.istc.sri.com> Sender: usenet@intercon.com (USENET The Magnificent) Reply-To: amanda@mermaid.intercon.com (Amanda Walker) Organization: InterCon Systems Corporation, Herndon, VA Lines: 40 One thing that no one has mentioned so far is that you can get in trouble by printing barcode on a 300 dpi printer for anything but your own internal use, unless you really know what you are doing. Most barcode symblogies are designed to withstand printing glitches and other distortions, but it is a lot harder to produce barcodes that are actually in spec than it is to just produces ones that scan OK most of the time. For internal inventory purposes, it's up to you to decide whether or not it's worth worrying about. However, if you are making things like UPC codes for retail packaging or LOGMARS labels for DoD shipments, you should bear some things in mind: - UPC cannot be printed in spec on a 300 dpi printer. At the standard symbol sizes, you need to be able to control the bar widths more finely than 1/300th of an inch. Something like a LaserMax or other "super resolution" printer may work, though, since it's a question of positioning accuracy, not resolution. Now, you can print *scannable* UPC & EAN (which is the European extension of UPC) symbols on anything down to a 72 dpi printer, which has proven useful for one-shot symbols such as weigh-it-yourself produce labels. For retail packaging, though, you should probably typeset it to be safe. - Most other codes are only in spec at specific sizes for a particular resolution, and at high resolutions you need to take the printer marking characteristics into account. For example, a high-density Code 39 symbol may be in spec on a write-black printer, but the same set of pixels on a write-white printer will be way out of spec. - Toner smear can quickly render a barcode symbol unscannable. If you are using a wand-type scanner, covering symbols with clear labels will greatly prolong their useful lives and save a lot of aggravation. For anyone doing serious work with barcodes, I suggest getting copies of the USD (Uniform Symbol Description) series of documents from AIM (Automatic Indentification Manufacturers), an automatic-ID technology clearinghouse. I don't have their address handy, but I can dig it up if anyone needs it. -- Amanda Walker, InterCon Systems Corporation -- Entropy requires no maintenance.