MUNBYN · 4 × 6 in
Print FBA box labels on a MUNBYN (4 × 6)
Set the paper size to 4 × 6 in (102 × 152 mm) in the MUNBYN driver, print at Scale 100% with margins set to None, and use a PDF whose page is exactly one 4 × 6 in label. Prepline turns Amazon’s label PDF into that file in your browser and remembers your printer’s offset after one test label.
The settings
| Setting | MUNBYN, 4 × 6 in |
|---|---|
| Paper size | 4 × 6 in (102 × 152 mm) |
| Scale | 100% (Actual size). Never “Fit to page”. |
| Margins | None |
| Orientation | Portrait |
| Headers and footers | Off |
| Media type | Labels with gaps (web / gap sensing) |
| Print resolution | 203 dpi, direct thermal |
Most MUNBYN printers ship with 4 × 6 rolls. Use them for FBA box labels and carrier labels: Prepline cuts each one out of a Letter page and puts it on its own 4 × 6 page.
Set up the MUNBYN once
- Add the paper size. Printing Preferences (Windows) or the printer’s Options (Mac): add the label size as a custom paper size.
- Teach it the label. Hold the feed button until it beeps to run the auto label-learning.
- Make the PDF. Drop Seller Central’s label PDF into Prepline (any layout, including the 30-up sheet), pick MUNBYN and 4 × 6 in. Each label lands on its own page of exactly that size.
- Print one test label and scan it with your phone. If it’s off by a millimetre, measure the two gaps on Prepline’s test label once and it’s fixed for good.
When it goes wrong
The sides are cut off
The page is bigger than the label. Seller Central’s PDF is a Letter page (or a 2.625 in sheet label), and the printer crops whatever doesn’t fit. Use a PDF whose page is exactly 4 × 6 in, print at Scale 100%, and keep the bars inside a 2 mm margin.
Two labels per sticker, or the label is tiny
The print dialog is shrinking a big page to fit, usually “Fit to page” or “Scale to fit”. Set Scale to 100% (Actual size) and choose 4 × 6 in as the paper size, not Letter.
A blank label between every label
The printer thinks the labels are longer than they are. Hold the feed button until it beeps to run the auto label-learning. Also check that the paper height in the driver is 6 in, not 6 in.
Everything is shifted a millimetre or two
Every printer feeds a little differently. Print Prepline’s test label (a frame 2 mm inside each edge), measure the left and top gaps, and Prepline moves all future labels by the difference. Saved for this printer.
The barcode won’t scan
Thin bars smeared by heat, or bars squeezed by scaling. Prepline draws every bar as whole printer dots (203 dpi), so check that Scale is 100%, lower the darkness one step if bars look fat, and scan the test label with a phone before the full run.
Questions
What paper size do I pick for 4 × 6 in labels on a MUNBYN?
4 × 6 in (102 × 152 mm). Choose it in the print dialog (or add it in the printer driver first), with Scale 100% and margins None.
Can I print FBA box labels on 4 × 6 thermal labels?
Yes. Seller Central offers thermal 4 × 6 box labels, and Prepline also cuts box labels out of a Letter page and puts each on its own 4 × 6 page, unchanged.
Do I need special software for the MUNBYN?
Only its normal driver. Prepline runs in the browser and gives you a PDF with the right page size, so any PDF viewer can print it.
Updated November 9, 2026