Shipping label prints cut off at the edge on a Mac

The label prints at the right size, in the right place, and one edge is missing. Usually the left. Sometimes a strip off the bottom.

This is nearly always margins, not the label, not the printer and not the file — and it is the one cause almost nobody checks, because the paper size looks correct.

The paper size is two settings, not one

When you define a custom paper size on macOS you give it dimensions and non-printable margins. Most people set the first and leave the second at its defaults.

Those defaults are meant for office printers, which physically cannot print to the edge of a sheet. They are typically around a quarter of an inch on each side. Applied to a 4x6 label that leaves a printable area of roughly 3.5 x 5.5 in — and macOS then fits the label into that, not into the 4x6 you typed.

So the size is right, the content is scaled down to fit an invisible smaller rectangle, and whatever sat at the edges is gone.

Fixing it

1. In the print dialog, open the Paper Size menu and choose Manage Custom Sizes.
2. Select your 4x6 size, or create one.
3. Set the dimensions to 4 x 6 in or 100 x 150 mm.
4. Set all four margins to 0. This is the step that matters.
5. Save, then select the size again in the print dialog.

Re-selecting matters: a print dialog holding the old definition keeps the old margins until the size is picked again.

When it is not the margins

Three other causes, in the order worth checking:

• Scale is not 100%. Fit-to-page can crop as well as shrink, depending on how the aspect ratios differ. Set it to 100% explicitly rather than trusting a default.
• The roll is narrower than the label. A 4x6 file on a three-inch roll loses the difference. Measure the roll rather than trusting the box.
• The printer is not calibrated. On a Zebra especially, poor media sensing shifts each label sideways or down until content falls off the edge — that is a calibration routine, not a setting.

Cut off at the bottom specifically

A missing strip along the bottom, rather than a side, usually means the content is longer than the label rather than misplaced.

The common cause is a label carrying an extra portion — a FedEx doc-tab, or a UPS quarter-inch stock size selected against plain 4x6 rolls. Turn the extra portion off, or load the stock it expects.

Check the file before blaming the printer

If the label was cropped by hand from a bigger page, the crop itself may have clipped it. Open the PDF and press Cmd+I in Preview: a page reading close to 100 x 150 mm is a good crop, while one that is noticeably narrower took the edge with it.

Our free browser tool leaves a small margin on purpose for exactly this reason — it errs towards including a little extra rather than risking a clipped barcode, because whitespace prints fine and a cut barcode does not.