Issue / Question
ZT400 Series Printer - Resolving Print Quality Issues
Applicable To
ZT400 Series
Resolution / Answer
Symptoms
- Light print or faded image
- Partially missing print or cut off
- Broken bars or lines in a barcode
- Poor or low barcode ANSI grade
- White lines in the print
- Streaks in the print
Causes
Media - Print quality is a product of proper printer setup and use of compatible media for the application. When ribbon is used for Thermal Transfer printing it must be compatible with the labels to ensure the printer meets the requirements the user is expecting. Proper matching of the labels/ribbon also assures the pressure and darkness settings don’t have to be at the extremes to print acceptably. Direct Thermal (no ribbon) labels must be approved for thermal printing applications since it does come in direct contact with the printhead.
Configuration - Printer setup includes properly adjusting the printhead pressure, setting the appropriate darkness level, and optimizing the print speed. In addition regular maintenance assures the printer is operating at an optimal level.
Important: All printer settings can be impacted by commands from a mis-matched or misconfigured driver or software application. A printer that is functioning fine after setup but fails or indicates an error after label requests are received are most likely affected by the host side misconfiguration of the driver or printer software settings. The host device that generates the printer commands for printing typically have setup configuration that send these as commands to the printer. Make sure all settings match the printer settings to avoid intermittent issues.
Problems and Resolutions
Note: Use the printer Pause Test Label when performing initial print quality adjustments. This will eliminate any issues introduced by the application or driver configurations. Read More>>
Problem
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Example |
Resolution
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Print is faded or too light when printing self test
Note: if the problem occurs after printing from your application, verify your driver/software configurations
Note: If there is a flood coating or preprint on the label surface where the print issue is occurring check with your supplier for corrective action.
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Click to Enlarge
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- Clean the Printhead. Contamination can cover the elements preventing heat transfer. Read More>>
- Try increasing the Burn Temp Read More>>
- Try increasing the printhead pressure
Adjusting the ZT400 Printhead Pressure Read More>>
- The media must be matched for the (ribbon if used) and if no ribbon is used verify the quality of the Direct Thermal stock. Check with your media supplier if you have tried all suggestions without success.
- Verify the ribbon is not slipping due to improper loading Read More>>
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Print is faded or too light on the left of right side.
What is left or right? Read More>>
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Click to Enlarge
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- The printhead pressure may need to be balanced.
- Balancing the Printhead Pressure Detail Read More>>
-ZT400 Printhead Pressure Read More>>
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Barcode ANSI grade is low or won't scan
Note: It is common to have the darkness
set too high and cause bar spreading. This may look visually better but it causes the spaces to be reduced lowering the barcode grade.
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- Darkness is too high or low. Try changing the darkness on the LCD Display. Also check the driver or application darkness settings. Read More>>
- Print the Feed Selftest Labels and note the barcode quality as the darkness changes. Read More>>
- Verify your quiet zone is 10x the narrow bar width. Barcodes too close to the edge may not scan
- Check for printhead element problems printing the Pause test. Missing elements can create problems with the bars in the barcode. Read More>>
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| The print is smearing or rubbing off |
Click to Enlarge
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- Media and ribbon mismatch - The ribbon ink will rub off the label if it is not matched for the media. Verify your ribbon and media are properly matched for your application.
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| The ribbon is wrinkling |
Click to Enlarge
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- Resolving Ribbon Wrinkle issues
Link to ribbon wrinkle resolution Read More>>
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| White lines in the print |
Click to Enlarge
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- Try cleaning the printhead elements. Build-up can cause lines in the print. Aggressive cleaing with cleaning film is sometimes needed if there is baked on residue that fails to be removed by swabs. Read More>>
- The printhead element(s) may have failed and the printer requires service.
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Image is cut off on the right
What is left or right? Read More>>
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Click to Enlarge
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- Verify the PRINT WIDTH is set correctly in the LCD Display and in the driver or application configurations. Read More>>
- If using ribbon assure the ribbon is the wider than the labels.
- Verify there is no debris or a label stuck to the printhead covering the print elements.
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Helpful Information
Balancing the Printhead Read More>>
Setting the Darkness Read More>>
Cleaning the Printhead Read More>>
How it works
There are two thermal printing methods: direct thermal and thermal transfer. Each method uses a thermal printhead that applies heat to the surface being marked. Thermal transfer printing uses a heated ribbon to produce durable, long-lasting images on a wide variety of materials. No ribbon is used in direct thermal printing, which creates the image directly on the printed material. Direct thermal media is more sensitive to light, heat and abrasion, which reduces the life of the printed material.
The printer uses a single row of heating elements in a printhead assembly that is pressed against a rubber roller called a platen. The printhead elements are heated as the ribbon (if used) and labels pass as they are pressed together to produce the image. Any factors that affect the transfer of heat being applied by the elements will result in print image problems (assuming the labels and ribbon are properly matched for the application).
- Printhead Maintenance – Failure to properly clean the printhead elements can result in an insulating build-up that prevents heat transfer. This can also lead to element failure.
- Printhead Pressure – The pressure must be sufficient to maintain a constant pressing of the printing media while the element heat is transferred. This pressure must be evenly distributed across the width of the label so the image transfer is at the same intensity.
- Burn Temperature – The darkness must be set high enough to meet the print darkness needed for the image transfer but not so high as to result in image spreading or burning of the ribbon carrier. Barcodes require that the bars and spaces are of equal width and increasing the darkness beyond those required can result in space width reduction and barcode scan failures
- Print Width - The Print Width value determines the maximum width the printer will print. Most often it is set to the full width and the label format determines the printed area based on the image location. Applications and drivers may set a print width and reduce the printable area based label size. This is not a problem unless one attempts to print outside the previously restricted area. Check the LCD Display if this occurs to see if the PRINT WIDTH was changed.
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