Last updated: 26 September 2026 · All guides
A thermal label printer is the single biggest time saver at a packing table. It needs no ink or toner, it prints a label in a second or two, and the label comes out already sticky. But most first-time setups go wrong in the same few places: the wrong paper size in the driver, a sensor that has not been calibrated, or an A4 marketplace sheet sent straight to a 4×6 roll. This guide walks through each of them in order.
What you need
- A thermal label printer. Most desktop models print at 203 dpi, which is plenty for shipping barcodes. TVS, TSC, Zebra and Xprinter models are all widely sold in India; the steps below apply to any of them.
- 4×6 inch direct thermal labels. Also sold as 100×150 mm. "Direct thermal" means the paper itself darkens with heat, so there is no ribbon to buy.
- The manufacturer's driver. Download it from the printer brand's own website rather than relying on the generic driver your computer picks automatically.
- A cropped label PDF. Marketplace label files are A4 pages with an invoice attached. They have to be cropped to the label first (step 3).
Step 1: Set the label size in the driver
This is the step people skip, and it causes most problems. Open your computer's printer settings, find the thermal printer, and open its Printing preferences (Windows) or the printer's page setup (Mac). Create or pick a paper size of 4 × 6 inches or 100 × 150 mm, portrait orientation.
Setting the size only inside a single print dialog is not enough. Many programs fall back to the driver's default the next time, so set it as the driver default once and it stays.
Step 2: Calibrate the label sensor
A thermal printer finds the start of each label using a small sensor that detects the gap between labels. Until it has measured your roll, it guesses, which is why a new printer often feeds a blank label or prints across two labels.
Most printers have a calibration routine that you start by holding the feed button for a few seconds until a few labels feed through. The exact method varies by model, so check your printer's manual. Run it again every time you load a roll from a different supplier, because label and gap sizes vary slightly between brands.
Step 3: Crop the marketplace label first
A Flipkart or Meesho label download is a full A4 page: the courier label at the top and a tax invoice below it. Sent to a 4×6 printer as it is, the whole A4 page gets shrunk onto the label, and the barcode comes out too small to scan.
Crop it first so each page is exactly one label. Our free Flipkart label crop tool and Meesho label crop tool do this in the browser. Choose Label only, and the output PDF's page size becomes the label size itself, so the printer does not have to guess.
Step 4: Choose the right print scale
In the print dialog, pick your thermal printer and set scaling to Actual size (sometimes called 100% or "None"). Avoid "Shrink oversized pages" and "Fit to page" when the file is already label-sized, because some PDF viewers add a margin and shrink the label slightly, which thins the barcode bars.
Check that orientation is portrait and that the paper size in the dialog shows 4×6 / 100×150 mm, not A4 or Letter.
Step 5: Adjust darkness and speed
Thermal drivers have a darkness (or density) setting and a speed setting. If text looks grey or the barcode bars look broken, raise darkness a step or two. If the bars look bold and start merging, lower it. Printing slower also gives darker, cleaner output on budget label stock.
Troubleshooting
| What you see | Most likely cause | Fix |
|---|---|---|
| A blank label between every print | Sensor not calibrated, or the driver paper size is longer than the label | Run calibration (step 2) and check the driver size (step 1) |
| Print starts halfway down the label | Calibration drift after changing rolls | Recalibrate with the new roll loaded |
| The label is tiny, in one corner | An uncropped A4 page was printed | Crop the PDF to label size first (step 3) |
| Faint print or white streaks | Darkness too low, or a dirty printhead | Raise darkness; clean the printhead as the manual describes |
| Right edge of the label is cut off | Paper size set to a narrower label, such as 3 inch | Set the driver to 4×6 / 100×150 mm |
| Labels fade after some weeks | Normal for direct thermal paper exposed to heat or sunlight | Print close to dispatch; store rolls somewhere cool and dark |
Keeping the printer healthy
Dust and adhesive from labels build up on the printhead over time and show up as thin white lines running through every label. Most manufacturers recommend wiping the printhead with an isopropyl alcohol swab or pen when you change rolls. Switch the printer off and let the head cool first, and follow the cleaning instructions in your printer's manual.
Buy labels from a consistent supplier where you can. Very cheap rolls sometimes have uneven gaps, which confuses the sensor, or a coating that prints grey no matter how high the darkness goes.