LabelChop

How to crop MyPost Business A4 labels to 4x6

MyPost Business exports A4 PDFs but your thermal printer needs 4x6. Here's how to crop labels manually and the faster automated way.

·7 minutes reading
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You downloaded a shipping label from MyPost Business. You sent it to your thermal printer. And what came out was either blank, cut off, or a tiny label squashed into one corner of the page.

The problem is simple: MyPost Business exports labels as A4 PDFs. Your thermal printer expects 4x6 (100x150mm). The two don't match, and nothing prints correctly until you fix the size.

Shipping packages ready for dispatch with printed labels

This is one of the most common frustrations for Australian eBay, Shopify, and Etsy sellers who've just bought a thermal printer. You've got the hardware, the labels are loaded, and the one thing stopping you is a PDF that's the wrong size.

Here's how to fix it.

In this article:

Why MyPost Business exports A4 labels

MyPost Business was built for standard office printers. Most Australian businesses print on A4 paper, so that's the default label format. When you generate a shipping label, you get a full A4 page with the actual label sitting in the top-left corner. The rest of the page is empty white space.

On an A4 laser or inkjet printer, this works fine. You print the page, peel the label from the sheet (or cut it out), and stick it on the parcel.

On a thermal printer, though, A4 is a disaster. Thermal printers use rolls of 4x6 labels, not sheets. When you send an A4 PDF to a thermal printer, it tries to shrink the entire page down to fit the 4x6 label. Your shipping label ends up the size of a postage stamp, and the barcode is unreadable.

Australia Post does offer an A6 setting (more on that below), but many sellers don't know about it. And if you're printing labels from eBay or a third-party platform that pulls from MyPost Business, you might not have access to that setting at all.

Change your MyPost Business label size to A6

Before trying to crop anything, check whether you can change the label format at the source.

  1. Log in to your MyPost Business account
  2. Go to Settings then Carriers
  3. Click the edit icon next to MyPost Business
  4. Under Print Settings, select A6 - 1 per page
  5. Save your changes

This tells MyPost Business to generate labels at A6 size (roughly 105x148mm), which is close enough to 4x6 that most thermal printers handle it without issues. Set your print dialog paper size to 4x6 (100x150mm) and you should be right.

A couple of catches:

  • International labels (CN23 customs forms) can only print on A4. This setting won't help for international orders.
  • If you're printing from eBay's bulk label tool or a platform like SellerDash or ShipStation, the label size might be controlled by that platform, not by your MyPost Business settings directly. Check the platform's print settings too.
  • Some sellers report that even after changing to A6, the PDF still has extra white space around the label. If that's happening, you'll still need to crop.

How to crop an A4 label to 4x6 manually

If you're stuck with A4 PDFs (international labels, platform limitations, or the A6 setting isn't quite right), you'll need to crop the label yourself.

Method 1: Adobe Acrobat "Take a Snapshot"

This is the method recommended by most thermal printer manufacturers including Rollo, MUNBYN, and Dymo.

  1. Open the A4 label PDF in Adobe Acrobat Reader (the free version)
  2. Go to Edit > Take a Snapshot (or Edit > More > Take a Snapshot in newer versions)
  3. Click and drag a rectangle around the shipping label only
  4. The selected area copies to your clipboard
  5. Go to File > Print
  6. Adobe should show a preview of just the selected area
  7. Make sure your thermal printer is selected and paper size is set to 4x6
  8. Print

This works, but it has problems. You're eyeballing the crop every single time. If your selection is slightly off, the label prints crooked or the barcode gets clipped. And you have to do this for every single label.

If you're shipping five orders a day, that's five times opening Adobe, selecting the snapshot tool, carefully dragging a box, and printing. At 20 or 30 orders, this gets old fast.

Method 2: Adobe Acrobat "Crop Pages" tool

The Crop Pages tool lets you set exact dimensions, which is more precise than the snapshot method.

  1. Open the PDF in Adobe Acrobat (the paid version, not Reader)
  2. Go to Tools > Edit PDF > Crop Pages (or right-click the page and select Crop Pages)
  3. Set the page size to 100mm x 150mm
  4. Adjust the crop box position so the label is centred
  5. Click OK, then print

The catch: this requires Adobe Acrobat Pro, which costs about $25 AUD per month. If you're already paying for it, great. If not, it's hard to justify a subscription just to crop shipping labels.

Also, Acrobat sometimes throws a "page size may not be reduced" error when you try to crop certain PDFs. This seems to happen more with labels generated through third-party platforms. When it does, you're back to the snapshot method or the workaround below.

Person working at a desk with ecommerce shipping supplies

The screenshot method (when Acrobat won't cooperate)

This is the method people fall back to when Adobe gives them trouble. It's not elegant, but it works.

  1. Open the A4 label PDF and zoom in until the label fills your screen
  2. Take a screenshot of just the label area (Snipping Tool on Windows, Command+Shift+4 on Mac)
  3. Open the screenshot in an image editor or paste it into a Word document
  4. Resize to roughly 100mm x 150mm (4x6 inches)
  5. Print to your thermal printer with paper size set to 4x6

The quality takes a hit because you're converting a vector PDF to a raster image. Barcodes can become blurry at lower resolutions. Australia Post scanners are fairly forgiving, but a low-resolution barcode will occasionally fail to scan at the post office or depot. Not ideal when you've got 15 parcels to get out the door.

Some sellers use a variation where they paste the screenshot into a Word or Google Docs template that's already set to 4x6 dimensions. That saves the resizing step, but you're still screenshotting every label.

On Reddit and eBay community forums, this is the most common workaround people share. It works in a pinch, but nobody actually enjoys doing it.

Skip the manual work altogether

Every method above boils down to the same thing: manual work for every single label. Open PDF, crop or screenshot, resize, print. Repeat for every order.

LabelChop was built specifically for this problem. It's a desktop app that watches your Downloads folder. When a MyPost Business A4 label lands in that folder, LabelChop detects it, crops the label to 4x6, and sends it to your thermal printer automatically.

Here's what happens:

  1. You generate a label in MyPost Business (or eBay, Shopify, Etsy, Amazon AU)
  2. The PDF downloads to your Downloads folder
  3. LabelChop detects it, crops the label from the A4 page, and prints it

That's it. No opening Adobe, no dragging selection boxes, no screenshots. The label is on your parcel before you've finished taping the box shut.

It works with Dymo, Zebra, Brother, MUNBYN, and any other 4x6 thermal printer. It handles labels positioned anywhere on the A4 page (top-left, centred, wherever MyPost Business decides to put them). And it handles multi-label PDFs too, splitting them into individual 4x6 prints.

It runs in your system tray, so there's nothing to click or manage after the initial setup. Pick your watch folder, pick your printer, and forget about it.

There's a 14-day free trial with no credit card required if you want to test it with your setup.

Ecommerce seller at a clean workspace ready to ship orders

Wrapping up

MyPost Business labels come as A4 PDFs because that's the default for standard printers. If you've got a thermal printer, you need those labels at 4x6.

Changing to A6 in your MyPost Business settings is the first thing to try. If that doesn't fully solve it (international labels, third-party platforms, leftover white space), you're left with manual cropping in Adobe or the screenshot workaround.

Both manual methods work. Neither is fun when you're shipping more than a handful of orders. If label cropping is eating into your packing time, give LabelChop a go. It takes about two minutes to set up, and you'll never open Adobe to crop a label again.