# Calibrating printers

Calibrating printers, and especially thermal label printers, is something that needs to be done every now and then in order to get the paper alignment correct and more.

## Calibrating a Zebra GK420d printer

### Step by step:

1. Turn on the printer.
2. Press and hold the Feed button for approx. 3-5 seconds, until the indicator LED flashes green once.
3. Release the Feed button.
4. The printer will feed out a few labels and complete the calibration automatically.

{% hint style="info" %}
Once completed, the printer stops feeding labels, and the status LED will show a solid green light.
{% endhint %}

### Verify Calibration (Print Configuration Label)

To ensure calibration was successful, print a configuration label:

* Press and hold the Feed button until the LED indicator flashes green twice, then release.
* A configuration label with printer settings will print out.

### Typical Problems Solved by Calibration:

* Labels feeding at incorrect lengths.
* Blank labels printed or labels feeding incorrectly.
* Labels stopping mid-label or between labels.

Calibration usually resolves these common label-feeding issues effectively.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.flowretail.com/docs/technical/configurations/calibrating-printers.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.