Labels that pass at the dock
Get a PTI case label out of a Zebra, Rollo, Munbyn, or Brother printer at exactly the right size — and confirm it scans before it ships.
Open the free label generator →Use the manufacturer's driver — ZDesigner for Zebra, or the vendor driver for Rollo, Munbyn, Brother, or TSC. In the driver's printing preferences, set the stock to exactly the label you loaded, for example 4 × 2 in. This matters more than any browser setting: if the driver believes the media is 4 × 6, everything scales and nothing lines up.
Print one label to an ordinary office printer at 100% scale and measure it with a ruler. If it does not come out at 4 × 2 in, the problem is scaling, not the thermal printer. Fix it here and the thermal print will be right the first time.
Four settings decide whether the label prints usable. Two of them are the reason most first attempts fail.
Background graphics matters because the Voice Pick Code prints white on a solid black box. With backgrounds off, that box comes out as an empty white rectangle and the code disappears.
Thermal bars bleed when the printhead runs too hot or the media moves too fast, and a bled barcode fails at the distribution center even though it looks fine to the eye. On a Zebra, start near darkness 15–20 and 3 ips, print one label, and look closely at the bar edges: they should be crisp, not fuzzy or joined. Lower the speed before raising the darkness.
This is the step that actually decides whether your cases are accepted. Scan the printed label with a handheld scanner or a phone barcode app. A correct GS1-128 decodes with its application identifiers intact — (01) GTIN, (13) pack date, (10) lot — and the UPC-A returns its twelve digits. If a packhouse has a barcode verifier, run a print-quality grade: receivers reject on print quality as often as on wrong data.
| What you see | Cause | Fix |
|---|---|---|
| Label prints at about half size | Scale set to "Fit to printable area" | Set scale to 100% and margins to None |
| Voice Pick Code is an empty box | Background graphics disabled | Enable background graphics in the print dialog |
| Content cut off at an edge | Printer's unprintable margin | Increase the bottom or side margin in the generator, not the driver |
| Bars look fine on screen, will not scan on paper | Darkness too high or speed too fast | Lower speed first, then adjust darkness; reprint and rescan |
| Two labels feed per print | Driver media size does not match the stock | Correct the media size in printing preferences and recalibrate the printer |
| Everything shifts left or right | Label sensor not calibrated | Run the printer's media calibration routine |
Any thermal printer with a Windows, macOS, or Linux driver will work, because the browser prints through the driver. That covers the common desktop units — Zebra ZD421 and GK420d, Rollo, Munbyn, Brother QL, TSC — as well as industrial print engines on a packing line.