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Section 4: Label Considerations

Perhaps as important as the type of printer used is the consideration given to the design and construction of the label itself. Again, this should be the subject of a specification, especially if you are expecting someone else to print the label for you. Most major companies have developed bar code labeling specifications to which they expect their suppliers to conform. If a shipment is received without a label or with one that does not meet the specification, the shipment may be rejected and, worse yet, a fine imposed on the supplier. A good label specification should, at a minimum, specify the following information:

  • The physical size and construction of the label.
  • The environmental specifications.
  • The symbology(s) to be used along with the technical specifications for the symbol.
  • The number, size, position and orientation of the fields along with the data to be contained in each.

Design

The design of the label is critical. If you are dealing with a simple item identification label containing nothing but a single bar code and its human readable information, then it is relatively simple. However, here you still may be required to make a tradeoff on whether to print the label horizontally across the label using a wider web printer or to print it vertically down the length of the label with a smaller web printer running slower. Complicating the decision would be the addition of images such as company logos and fancy human readable printing such as commonly found on retail bar code tags.

  • SIZE
    The physical size of the label must be within reasonable limits. One too small is difficult for klutzy fingers to position precisely, while a very large label is almost impossible to apply without creating a wrinkle (which can destroy the readability of the bar code). As a general rule, labels as small 1/2' high by 1" long and as large as 5" high by 7" long can be applied manually without too much difficulty.
  • MULTIPLE BAR CODES
    As soon as more than one bar code is included on the label, the problem of which one is read by the scanner must be addressed. This can be solved by using different symbologies for each bar code or by including a "Data Identifier" character at the start of the data string. The two symbology approach is generally discouraged, since it requires two symbologies with similar structures and data encoding capabilities. Another way to separate two different bar code symbols is to place them at right angles to each other, but problems appear again when more than two symbols are needed.

    Multiple bar code labels must face another problem, that of how the operator knows which symbol was scanned. This is not difficult if a hand wand scanner is used, but a moving beam laser operator has no control over the horizontal scanning of the beam, just how it is vertically positioned. It is difficult to control which symbol is being read if they are both placed side by side. In this case, stacking the symbols vertically, will solve the problem since the beam can never cut through more than one complete symbol. All of these problems can be eliminated by use of industry standard Data Identifiers to identify the data contained in the symbol.

    The placement and orientation of the fields can have a significant effect on the success of a bar code system. If there is information on the label that must be read by an operator, then it should be presented in a highly visible area in a font that will maximize readability. Bar code fields should be easily identified by the operator who must do the scanning.
  • QUIET ZONE
    One of the most common mistakes made in label layout is the failure to Quiet Zones at the beginning and end of the bar code. This is blank space free of any printing or marks. It is needed by the decoder to establish the end points of the symbol. While the decoder may be able to resolve a Quiet Zone that is at least 10 times the smallest bar dimension, the Quiet Zone should never be less than 0.25". Even at that size, hand scanning with a wand is difficult because hand motion is very erratic at the beginning and end of the scan. Placing the bar code too close to the edge of the label violates the Quiet Zone rule even if the label is placed on a white surface. The scanner may detect the raised label edge as a non-reflective bar.


Basic Program and Label

Design Software

After deciding what the label should look like, the next problem encountered is how to create it. There are two options, you can either include sufficient write your own program or use a software package to do it for you. If the number of different label designs is small, and the data on them is minimal, it is relatively easy to write a small program to do the job. The Basic program shown in the illustration will print the example label shown on a SATO M-8400RV printer. It has only three fields, one a bar code with HRI information printed below it and two text fields surrounded by a box. However, the day when the process consisted of sending a line of characters down to a text printer to be printed upon a receipt of a carriage return is long gone. Now you have to specify the font, how large it is, where the characters are to be placed, the orientation of the field, what type of bar code, etc.

The AIAG shipping label illustrates the problem of complex label designs. It typically contains 29 fields that must be separately programmed along with eight border lines. Also, the information contained in the fields can, and probably will, vary from label to label. Even if we manage to get all of the fields programmed correctly, we still have to find a way to easily enter the variable data into the fields without writing a new program each time. We are talking serious programming here with "GO TO" statements, "LOOPS" and other esoteric jargon.

It is obvious that we need something to insulate us from this process. A label design and software package is in order. The definition of a "good" label design package depends upon the label to be designed. For a simple layout, a basic text-based program asking you to enter coordinates and information with a menu driven screen is acceptable. However, more complex labels are difficult to visualize using this method. A WYSIWYG screen layout program is preferred.

One caveat is in order, even though a label design program allows you to do all sorts of fancy things, unless the capability is needed, it can end up complicating your life. The only person that becomes proficient in using a complicated label design program is one that uses it a lot. This is not the normal case in the industry, where it is more likely that a few standard labels will be designed and used over and over. For this reason, an intuitive design program is desired, one where you do not spend a lot of time trying to understand how to use the program. A Windows based program would be a good choice, since it has a user interface that is familiar to most people. A Windows design screen from SATO's Label Wizard program illustrates the advantages. It provides a user-friendly interface that insulates the user from the intricacies of the design process.


Typical AIAG Shipping Label

A demo copy of Label Wizard can be downloaded free from the SATO home page on the internet (http://www.satoamerica.com). This is a complete functional version of the program and contains all of the features and capabilities of Label Wizard except for production printing. All of the label formats designed with this version can be used if a decision is made to upgrade to the full production version of Label Wizard at a later date.

Printing
Most label design programs will allow you to print labels directly from the program. Sometimes this is not the way to go. If the operator only needs to print labels, there is no need to supply access to the design part of the program. As a matter of fact, it is probably desirable to limit access since the temptation to "improve" the design is eliminated. Being able to break the print portion out into a print only stand-alone program (referred to as a Run Time program) is the best solution. The operator then has to select the right label design from a list and identify the source of the data for the fields.

If the labels are to be used in a production environment, the ability to automatically access external database files for the contents of variable fields is a necessity. By defining the field as a variable and tying it to a database, the information can be automatically placed in the field at the time of printing. This allows all database management to be confined to the primary database and any updates or changes automatically incorporated into the label without having to modify the label printing job. The database types can be supported by the program directly or indirectly through the new Microsoft ODBC (Open Database Connectivity) specification.

  • WINDOWS PRINTER DRIVER
    Sometimes it is desirable to be able to print directly to a bar code printer from a standard Windows application program. To do this you need to load the printer as a standard Windows printer. A Windows Printer Driver is available for many of the more popular bar code printers. Windows drivers for SATO printers are available free of charge from SATO. These drivers support all of the bar code symbologies resident in the SATO printers. This allows precise control of the bar code to ensure that it is printed within specifications.
  • USING TrueType� BAR CODE FONTS
    Bar codes can be printed from standard Windows applications using bar code TrueType� fonts, of which a number are available from different sources. These can be used successfully with the SATO Windows Printer Driver, but extreme care must be used to ensure that readable bar codes are printed. There are several areas in which careful attention must be made:
    • Type Size - By design, TrueType� fonts are scalable fonts. You specify a type size and the computer generates the best fit using the resolution of the printer. This works great for human readable fonts, but can cause problems with bar code fonts. For example, the TrueType� expansion algorithm tries to make the font outline smooth and decides when an element is printed with one dot versus going to the next size by adding another dot. When printing bar code fonts, this can cause variations in the relative bar widths, resulting in an unreadable bar code. TrueType bar code fonts are designed to be printed at specific type sizes using a certain resolution printer. Using a different type size or a different resolution printer can destroy the critical bar width relationship of the bar code.
    • Start/Stop and Check Digit Characters -When data is input for TrueType� fonts, any necessary start/stop or check digit characters must be included.
    • Data Input - Some bar codes support a number of character sets, many of which are not present on a typical PC keyboard. The TrueType font must assign some key combination for these characters.
    • Graphics - All TrueType text information is sent in a graphics format, including bar code symbols. This greatly increases the transmission time required for each label.


Label Wizard Windows Design Screen

Copyright � 1998
Sato America, Inc.

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