1. ZT211 Industrial Printer User Guide
  2. Diagnostics and Troubleshooting
  3. Evaluating Barcode Quality
  • ZT211 Industrial Printer User Guide
Evaluating Barcode Quality
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Evaluating Barcode Quality

Different types of media may require different darkness settings. This section contains a simple but effective method for determining the ideal darkness for printing barcodes that are within specifications.
During the FEED self test, labels are printed at different darkness settings at two different print speeds. The relative darkness and the print speed are printed on each label. The barcodes on these labels may be ANSI-graded to check print quality.
During this test, one set of labels is printed at 2 ips, and another set is printed at 6 ips. The darkness value starts at three settings lower than the printer’s current darkness value (relative darkness of –3) and increase until the darkness is three settings higher than the current darkness value (relative darkness of +3).
  1. Print a configuration label to show the printer’s current settings.
  2. Turn off (O) the printer.
  3. Press and hold
    FEED
     while turning on (I) the printer. Hold
    FEED
     until the first control panel light turns off.
    The printer prints a series of labels at various speeds and at darkness settings higher and lower than the darkness value shown on the configuration label.
    FEED Test Label
  4. Inspect these test labels and determine which one has the optimal print quality for your application. If you have a barcode verifier, use it to measure bars/spaces and calculate the print contrast. If you do not have a barcode verifier, use your eyes or the system scanner to choose the optimal darkness setting based on the labels printed in this self test.
    Evaluating Barcode Quality
    Appearance
    Description
    Too dark labels
    Fairly obvious. These may be readable but are not “in-spec.”
    • The normal barcode bars increase in size.
    • The openings in small alphanumeric characters may fill in with ink.
    • Rotated barcode bars and spaces run together.
    Slightly dark labels
    Not as obvious as the too-dark labels.
    • The normal barcode will be “in-spec.”
    • Small alphanumeric characters will be bold, and may appear slightly filled in.
    • The rotated barcode spaces are small when compared to the “in-spec” code, possibly making the code unreadable.
    “In-spec” labels
    Whether or not a label is “in-spec” can only be confirmed by a verifier, but they typically exhibit some visible characteristics.
    • The normal barcode will have complete, even bars along with clear, distinct spaces.
    • The rotated barcode will have complete, even bars along with clear, distinct spaces. Although it may not look as good as a slightly dark barcode, the barcode will be “in-spec.”
    • In both normal and rotated styles, small alphanumeric characters will look complete.
    Slightly light labels
    In some cases, these are preferred to slightly dark ones for “in-spec” barcodes.
    • Both normal and rotated barcodes will be “in-spec,” but small alphanumeric characters may not be complete.
    Too light labels
    These are obvious.
    • Both normal and rotated barcodes have incomplete bars and spaces.
    • Small alphanumeric characters are unreadable.
  5. Note the relative darkness value and the print speed printed on the best test label.
  6. Add or subtract the relative darkness value from the darkness value specified on the configuration label. The resulting numeric value is the optimal darkness value for that specific label/ribbon combination and print speed.
  7. If necessary, change the darkness value to the darkness value on the selected test label.
  8. If necessary, change the print speed to the same speed as on the selected test label.