# Label printing GeoDin Onsite can print barcoded sample labels directly from your field forms, giving every sample a unique traceable ID. This page covers the Labels tab in Configuration — printer setup and label customisation. For the actual label-printing workflow, see [Managing labels](/geodin-onsite/guides/managing-labels.md). ## Printer technology Onsite prints labels in **ZPL** (Zebra Programming Language), an industry-standard language for thermal label printers. The Zebra brand is the market leader, but any printer advertising ZPL compatibility should work. {% hint style="danger" %} Windows print queues — including "Microsoft Print to PDF" — are **not** ZPL compatible and will not print labels correctly, even though they may appear in Onsite's printer dropdown. You need an actual ZPL-compatible thermal printer. {% endhint %} ## Configuring printers Onsite lets you configure **two printers** — a main printer and an alternative printer. This covers common field and lab use cases: * A laboratory with white labels on one printer and red labels (for hazardous samples) on another * Different label sizes — small labels for vials, large labels for containers * A backup printer for when the main one is busy Set them in Configuration → Labels: * **Main printer** — the default printer for regular labels * **Alternative printer** — a secondary printer, selected per-label when needed * **No printer** — disables printing * **Preview** — shows the label on screen without actually printing; useful for testing label templates
## Recommended hardware For the smoothest experience, we recommend the **Zebra ZQ600 Series mobile thermal label printer**. 👉 Buy or view details: [Zebra ZQ600 Series](https://www.zebra.com/us/en/products/printers/mobile/zq600-series.html) Other, equivalent ZPL-compatible thermal label printers may also work, but this model has been fully tested with GeoDin Onsite. ## Custom button labels If "Alternative printer" and "Alternative label layout" don't describe your setup meaningfully, rename them. Onsite lets you replace the default text on the printer toggle and label-layout toggle buttons. For example: * "Use alternative printer" → "Use printer next door" * "Use alternative label layout" → "Use hazardous layout" Custom names live in the Labels tab settings. A clearer button label saves confusion in the field. ## Label templates Onsite ships with default label templates stored in the installation folder at `\assets\labels\` (read-only). The defaults produce a 2″ × 2″ label (approximately 50 × 50 mm) with the GeoDin logo and standard sample identification fields. ### Two template slots You can configure two templates — main and alternative — matching the two-printer setup. The main is for everyday labels; the alternative covers a second use case like hazardous-sample labelling. ### Customising a template To use a custom label design: 1. Copy the default `.zpl` file from the installation folder to your [working folder](/geodin-onsite/core-concepts/folder-structure.md). Rename it, for example `my-qr.zpl`. 2. Edit the file to match your design. The template uses `{field}` placeholders for sample data — project number, location, depth, barcode text, and other values Onsite fills in at print time. 3. In Configuration → Labels, set the label template filename to your custom file (`my-qr.zpl`). Onsite uses the file from your working folder in preference to the default. {% hint style="info" %} **Zebra Designer** is a free visual tool from Zebra for designing labels. Design the layout graphically, then save it as a `.zpl` file ready to use with Onsite. {% endhint %} ## Logo customisation The default label template includes the GeoDin logo. To replace it with your organisation's logo: 1. Prepare a PNG image of your logo. The default logo is 478 × 376 pixels — match the aspect ratio closely for best results. Use a white background. 2. Save the file as `logo.png` in your [working folder](/geodin-onsite/core-concepts/folder-structure.md). 3. The logo applies immediately — no restart needed. The same `logo.png` is also used on exported PDFs of forms, keeping your branding consistent across labels and reports. ## Sample ID format Every sample gets an automatic unique identifier consisting of a prefix, a timestamp-encoded section, and a random suffix. By default the prefix is a single letter, but you can customise it to 1–3 letters to match your organisation's sample-identifier convention. The prefix and random suffix together always total **5 characters** — a longer prefix shortens the random section correspondingly. A 1-character prefix has 4 random characters, a 2-character prefix has 3, and a 3-character prefix has 2. The timestamp-encoded section in the middle is independent of this. *** **See also** * [Managing labels](/geodin-onsite/guides/managing-labels.md) — the label tools in the Tools menu * [Soil sampling](/geodin-onsite/guides/soil-sampling.md) — taking samples in G1 forms * [Folder structure](/geodin-onsite/core-concepts/folder-structure.md) — where logo and template files live --- # 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.geodin.com/geodin-onsite/configuration/label-printing.md?ask= ``` 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.