# Printronix: GAP NOT DETECTED

A “GAP NOT DETECTED” error means that the printer was not able to find the gap/mark between labels. There are a few potential causes for this error:

1. The printer has not performed a media calibration on the labels
    - <span style="white-space: pre-wrap;">Solution: </span>[Calibrate your printer.](https://kb.simplerfid.com/books/calibrate-printer/page/calibrate-your-printer "Calibrate your printer")
2. The labels are not feeding out of the printer correctly (most often because the labels were back-fed too far into the printer)
    - <span style="white-space: pre-wrap;">Solution: Ensure that at least 1 label is sitting past the </span>[platen roller](https://kb.simplerfid.com/books/printers/page/what-is-a-platen-roller).
3. The media sensor is in the wrong place (it should be underneath the labels, lined up with the gap)
    - Solution: Ensure that the media sensor is sitting directly under the labels, so the gap between the labels will pass over the sensor when feeding/calibrating.
    - After adjusting the sensor, please calibrate your printer again.
4. The printer is set to the wrong media type (Gap vs. Mark)
    - <span style="white-space: pre-wrap;">Solution: Ensure that the </span>****Sensors &gt; Control &gt; Gap/Mark Sensor**** is set to the value that matches your labels (e.g. Gap).