Printing UPS shipping labels on a Mac

Start with the thing that invalidates most UPS advice you will find: WorldShip does not run on macOS. It is a Windows application, so every walkthrough describing Label Configuration and Label Stock Dimensions is describing software you do not have.

On a Mac you ship through ups.com or CampusShip in a browser. Fewer options, and the ones that matter are in a different place.

Choosing the format on ups.com

When the shipment is ready, UPS asks how you want the label. The choice is between a full 8.5 x 11 page and a thermal 4 x 6, and it decides everything that follows.

Pick the thermal option and the PDF arrives already the size of your roll: set the paper size to 4x6, scale to 100%, and it prints correctly with nothing else to do.

The Letter option is not broken — it is meant for office paper, folded and taped to the parcel. It only becomes a problem when it meets a thermal printer.

The quarter-inch sizes, and when they hurt

UPS documentation refers to 4x6, 4x6¼, 4x8 and 4x8¼. Those are real, different stocks rather than rounding.

• 4x6 — plain shipping label. What almost every roll sold for home and small-business use actually is.
• 4x6¼ and 4x8¼ — stock with an extended area for a tear-off or additional printed portion.
• 4x8 — longer stock, used where a document portion prints with the label.

Selecting a quarter-inch size while plain 4x6 is loaded pushes the last few millimetres of the label past the end of the physical label. It usually takes the bottom of a barcode with it, which is the kind of failure you find at the counter rather than at the printer. Match the selection to what is on the roll.

Printing it

1. Download the PDF rather than printing from the browser tab.
2. Open it in Preview, then File → Print and Show Details.
3. Select the thermal printer first — that populates the size list.
4. Set Paper Size to 4 x 6 or 100 x 150 mm.
5. Set Scale to 100%. Not fit-to-page, which undoes the format you just chose.

Printing straight from the browser is where the Letter version usually sneaks through: browsers apply their own scaling and margins, and the result looks nothing like the same file printed from Preview.

When you end up with the Letter version anyway

It happens — a saved preference, a return label generated by someone else, a label forwarded to you. The label is then a rectangle on a full page, and no print setting fixes that: the page has to be cut down first.

Our free browser tool does that in a few seconds — it finds the label, crops without rescaling so the barcode is untouched, and never uploads your file.

Return labels are a separate case

A UPS return label generated for a customer, or received from a sender, arrives in whatever format they chose — normally Letter, because that is what someone printing at home needs.

You cannot change how it was generated. That one really does have to be cropped, which is worth knowing before you go looking for a setting that is not on your side of the transaction.

If the label prints but scans badly

UPS barcodes are dense, and a thermal printer at low density produces bars with soft edges that a scanner rejects even though the label looks fine to you. That has its own guide, because the fix is on the printer rather than in the file.