Gap Sensing Error. Label alignment is printing vertically offset. There is a white line/gap at the top or bottom of my label. The image is printing too far down the label or too early (LX Series).

Top of Form (Vertical) Alignment: Gap Sensing Error. Label stock is not loading. Label alignment is printing vertically offset. There is a white line/gap at the top or bottom of my label. The image is printing too far down the label or too early (LX Series).

If labels are printing horizontally offset, try the solutions in this article: Labels are printing horizontally offset (left to right). The image is printing too far to the left or right.

The LX series printer decides where to start printing by detecting the gaps between labels or detecting a black mark on the back.

The following items can cause the label sensor to improperly detect the start of a label:

1. Label Stock Loading. The label stock is not loaded properly. See this article for loading tips.

2. Print File Setup (Margins and Page Size) Make sure all margins are set to zero! Make sure your page size and template size match your label stock. Often, the page size is not large enough for the label.  If this is the case, you may see white space on the right (printer's left) side of the label and no image overlap on the opposite side.  This indicates that the page size needs to be increased.  Increase the page size through the printer preferences enough to cover the label.

For PC using Bartender, follow this label setup guide.  



For Mac using Swift Publisher follow this label setup guide.

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3. Sensor Position. Circular, nonstandard label shapes or multiple labels across will require precise adjustment of the label sensor. (For LX910, LX3000 and LX4000 follow this article). If you are using circular or other nonrectangular die-cut labels, make sure the sensor is set to the very top of the label where the shapes are closest together. If the sensor is too far to the right or the left, the printer will still sense the label, but the image may be offset downward because the printer will start printing at the wrong position. If you are using stock that has multiple labels across, make sure the sensor corresponds to a place on the stock that has a label and not a vertical gap. The sensor can be adjusted using the slide bar on the inside of the printer. Below the slide bar is a measurement that represents the distance between the edge of the label stock and the sensor. Measure the distance from the edge of the label stock to the correct position on the stock. Set the sensor to this measurement. For specific instructions for your printer model, refer to the user's manual. 

4. Stuck Label.  Part of a label, dust, or debris could be caught in the sensor area.  Using canned air, blow out the infeed area. Over time, dust or label debris can accumulate there and cause sensing problems. The label stock should be removed before attempting this procedure.  Follow this article for full instructions on removing a stuck label. 

5. TOF Offset. TOF stands for Top of Form, and this setting allows you to fine-tune the alignment of your printing on your label stock. This will be factory-calibrated. If fine-tuning is needed, adjust Top of Form alignment using the PrintHub or the config utility on Mac. Go to the Print Alignment Tab. This value moves the print start position up or down on the label. Add to the current value to move the printed label down or toward the printer. Subtract from the current value to move the printed label up or away from the printer. The value is automatically saved as soon as you set it. You may have to make several adjustments to one or more of these values. After each adjustment, you can click the Test Alignment button to print a small test pattern on the label. This will help you find the proper alignment value.
 

6. Preprinted Stock. Preprinted stock is not recommended but can be accommodated if you move the sensor position. See 8 below. The preprinted sections may be visible by the sensor through the back of the label. If you can move the sensor position to place on the label where there is no printing it may be possible to detect the start of the label.

7. Rewinder. If you are using an automatic label rewinder such as the Primera RW-12, it may be affecting vertical and horizontal alignment. This is especially true if your labels are less than 4" wide. Follow the tips in this article to solve this issue.

8. Nonstandard / Non-translucent Backing Material. Test the unit with the label sample material that came with the unit. If it prints correctly, your label stock may not be compatible. The label sensor needs to see the difference between a label and a backing material by seeing through the label stock for light variations. If it cannot see through the label, problems will arise. If you must use this type of backing, try label stock that has a black mark on the back to show where the label begins. You will need to change the Sensor Type setting in the driver preferences to Reflective.

9. Improper Label Gap Distance. . 125" (3.17mm) is the standard gap. If the gap between labels is too small, there will not be enough time for the gap to be detected. See the Label Specifications section in the user manual for your printer.

10. Page Size does not match Label Stock Size. If you are using BarTender follow this label setup guide. For all other programs, if the page size set in the driver is larger than the actual label stock, ink will be printed on the gaps and the sensor will start looking for a gap too late. This can cause label skipping or inconsistent print starting points. If it is too small the label can get cut off exposing white space on the label. 

11. Portrait / Landscape. If the Letter / Landscape setting does not correspond to the label stock installed, this will also cause the printer to print over the gap and onto the next label. Make sure this is set correctly. See this article.

12. Dirty encoder strip. If the encoder strip or label sensor is dirty, the printer cannot detect the gap between labels. Try gently cleaning the encoder strip (the clear plastic strip that runs through the back of the print head) using isopropyl alcohol and a paper towel or alcohol wipe. Follow this article.

Related Articles:

Labels are printing horizontally offset (left to right). The image is printing too far to the left or right.

How do I correctly load label stock?

Article ID: 44796