Print Posti labels on a thermal label printer (107 mm thermo)

Posti delivers its address labels ("osoitekortti") as PDF files from SmartShip, OmaPosti Pro, its API and the Posti Shipping plugins. Posti does not document a 100×150 mm label: its thermal formats are 107 mm wide, so set up the printer, labels and driver for that size.

Posti label formats

Posti's SmartShip and OmaPosti Pro API guides list these formats (media names in brackets).

For a thermal printer, use one of the two thermo formats.

Choose the thermo format in your Posti tool

• SmartShip (smartship.unifaun.com) is Posti's tool for printing shipping documents and ordering pickups. Start a shipment under "Lähetysasiakirjat" (Shipping documents), move through the forms with "Seuraava" (Next) and print with "Tulosta PDF" (Print PDF).
• OmaPosti Pro (pro.posti.fi) is Posti's portal for sending, tracking and reporting.
• Your own integration: in the SmartShip REST and OmaPosti Pro APIs, set the label media in pdfConfig (target1Media) to thermo-225 or thermo-se. The label comes back as a PDF; the guides describe no ZPL output.

Posti's public guides do not show where the label format is chosen in the SmartShip and OmaPosti Pro web screens. If your labels arrive as A5 pages, ask Posti business customer service how to get them in the 107×225 mm or 107×251 mm thermo format.

Check the page size in the PDF reader's document properties: it should match the thermo format, not A4 or A5.

Load 107 mm labels and calibrate

A 107 mm label fits these printers. On models with a 104 mm print width, the print width is slightly narrower than the label, so the outermost millimetres stay unprinted.

1. Load the roll with the printable side facing the printhead and set the media guides to the 107 mm width.
2. On a thermal transfer model, remove the ribbon for direct thermal labels and set the driver to direct thermal printing.
3. Calibrate so the printer learns the new label length: see ZD220/ZD230, ZD421 or ZD621 calibration, TSC DA210/DA220 calibration or PC42E calibration.

Set the label size in the driver

Enter the size of the Posti format: 107 mm wide and 225 mm high, or 251 mm high for the STE label.

• Zebra (ZDesigner): open Printing preferences, then Page Setup › Media Settings. Under Print Options, set Printing mode to Thermal Direct.
• TSC: open Printing preferences, then Page Setup › Stock › New, enter a name, the width and the height, and click OK.
• Honeywell (InterDriver): set the same label size in the driver's printing preferences.

The brand guides explain these driver settings in detail for 100×150 mm labels. The steps are the same; only the size differs: Zebra, TSC and Honeywell PC42E.

Print the PDF and test it

1. Open the label PDF and choose Print. Select your label printer and check that the paper size shows the Posti label size.
2. If the PDF page is exactly the label size, print at actual size (100 %). For any other page size, use "Fit to page" (Zebra recommends fitting PDFs to the paper size). Never fit an A5 or A4 page onto one thermal label.
3. Choose portrait, or let the program pick the orientation.
4. Print one label. Scan every barcode and check that no text or barcode is cut at the edges.
5. If the print is pale or a barcode won't scan, raise the darkness one step at a time in the driver, or lower the print speed.

Print from Shopify or WooCommerce

Posti publishes its own Posti Shipping plugin for both platforms. It needs Posti API credentials, which you can order only with an existing Posti logistics contract.

• Shopify: install Posti Shipping by Posti Oy. In the order, choose More actions › Print labels & fulfill to create the shipment, the tracking number and the label. The sender address on the label is set under Apps › Posti Shipping › Asetukset › Lähettäjän tiedot (Settings › Sender details).
• WooCommerce: install Posti Shipping by Posti. Open the order and use "Luo pakettikortti" (Create parcel card) in the Posti section, or create labels for several orders from the order list. The plugin has supported different label sizes since version 3.7.0, but Posti doesn't list which. Look in its settings under WooCommerce › Asetukset › Toimitus › Posti (Settings › Shipping › Posti), and ask Posti if no thermo size is offered.

The printer setup above applies to labels from the plugins too. See also Shopify shipping labels and WooCommerce shipping labels.

Attach the label

• Put the label on the largest flat surface of the parcel, not over an edge or a closing seam, where it could fold and make the barcode unreadable.
• Don't cover the label with tape, string or strapping. Put documents such as an invoice in a plastic pocket next to the label.
• Parcels to a Posti parcel locker ("pakettiautomaatti") need the recipient's mobile phone number in the shipment details.

Common problems