See whether the printer skips stock or the job sends an extra page
Pause the batch and wait for the printer to become idle. On a machine with a documented one-label Feed action, use it once with the usual stock loaded. Check whether it stops at the next label in the expected position. If needed, repeat once to see whether the result is consistent. A feed check on a model that uses a fixed-length or continuous setting needs to be interpreted according to its manual.
Now send one page from a known correctly sized file. Compare what advances during the feed check with what advances during the job. If the printer feeds normally when idle but produces a blank only after a particular file, check that file and its print settings. If it keeps passing whole labels without a print job, examine how the printer is detecting the stock.
| What you see | First check | Next step |
|---|---|---|
| One blank label when you load stock | Model’s loading behaviour | Wait for it to settle and run one normal feed |
| Two or more labels advance on each idle feed | Stock path and sensing type | Set up the media and run the model’s calibration |
| Extra blank only with a particular PDF | Page count and preview | Print just the intended postage page |
| Each print starts farther down the next label | Physical label length, gap and paper setting | Correct the dimensions and check feed calibration |
| Print position jumps when the stack moves | Resistance or sideways pull | Straighten the feed path and adjust the guides |
Check the backing and give the stock a straight path
Inspect the liner. Most ordinary die-cut labels have a visible space between label faces. Black-mark media uses a printed positioning mark, commonly on the reverse. Continuous media has no repeating gap or mark. Set the printer or driver for the stock it can detect. A perforation for tearing off a strip can be separate from the feature the sensor reads.
Check the paper guides, roll holder or stack position. Guides should keep the supply straight while leaving it free to move. Make sure an external roll can turn freely and a fanfold stack has space for the next fold to open. A stack pulling to one side can cause a variable fault that appears only after several labels.
If you changed the backing colour, coating or stock supplier just before the problem started, try a small amount of previously working stock. This is a quick way to compare the paper path and sensing behaviour with the setup you know. Keep the dimensions and print file the same where possible so the result tells you about the stock.
Make the file, loaded label and selected paper size agree
Measure the printable label face from leading edge to trailing edge. Measure a gap separately if your driver asks for it. The length from one leading edge to the next includes the gap, so use the model’s instructions for what to enter in each field.
Select the intended printer and paper size in the PDF viewer or label app. Exact 4×6 inches and 100 × 150 mm are close but different. A job configured for an A4 page can also advance stock differently from a job created for one thermal label. If the preview contains postage, instructions and a blank page, print only the carrier’s required postage page in the format for your stock.
Some drivers let a print job override the saved paper size. If a known template feeds normally but a new marketplace download skips, compare the settings shown in that job. For an image that begins the same few millimetres off on every correctly advancing label, review page layout and the supported offset setting separately.
Use the routine for your printer and the fault you see
MUNBYN RW403B. MUNBYN’s skip procedure calls for at least four consecutive labels loaded. After closing the cover, let the machine attempt its automatic feed. If it does not do so, the support article describes holding Feed until the beep to run label identification. Then check one ordinary feed and one print.
The RW403B also has a separate procedure for a solid red light, an unresponsive Feed button or a false out-of-paper warning. That sensor calibration starts with the machine off and empty. Use MUNBYN’s specific red-light instructions if those are the symptoms.
Zebra ZD421 and ZD621. Zebra documents SmartCal for loaded media. Check the sensing method first. Where you are using black-mark stock, follow the guide for lining up the sensor with the mark. Zebra also documents manual media calibration for media that SmartCal fails to recognise. Use the instructions for the exact printer and configuration.
For a Brother QL machine, start with the model’s supported DK roll and installation guide. The printer and its DK holder use a different supply arrangement from the two open-format examples. Select the correct DK roll size in the print settings and use Brother’s own procedure if the roll will not feed correctly.
Confirm a short run before restarting the batch
Check that one feed stops at the expected boundary. Print one correctly sized sample, then run a small batch to see whether the start position stays consistent. If the first print aligns and subsequent prints shift, record the stock dimensions and spacing and check for drag as the supply moves.
When the fault persists, note whether it occurs during idle Feed, every job or just one file. Record the model, connection, media type, dimensions and any warning light. A short video of the feed can help the manufacturer identify the issue without sharing a postage label containing a customer address.
Manufacturer feed and calibration instructions
Checked in November 2026.
Common questions
Why does my thermal printer print every other label?
First check whether a normal Feed action also advances two labels. If it does, check sensing, the physical stock and calibration. If Feed advances one correctly, check the document’s pages and the selected label length in the print dialogue or app.
Is one blank label after loading paper normal?
Some printers advance blank stock to locate the first printable label. MUNBYN describes this behaviour for the RW403B on loading. If it keeps happening during a print job, test the feed and check the job settings.
Does 100 × 150 mm count as 4×6 inches in my printer?
Exact 4×6 inches is 101.6 × 152.4 mm. Choose the dimensions of your actual label stock and a corresponding carrier output. A size preset with a similar name can set a different feed length.
Should I calibrate after changing from gap stock to black-mark labels?
Check that the exact printer supports the new sensing method. Where the sensor is movable, follow the instructions for aligning it with the mark. Run the calibration procedure for the model and the loaded stock.
Do skipped labels mean the printer needs a new printhead?
If it can print clearly on some labels, start with feed, sensing and page settings. A short feed test and one correctly sized sample job can separate skipped stock from a fault that affects the printed image itself.