Choosing a 4×6 thermal label printer for small sellers

A direct thermal printer uses heat to darken special label paper. There’s no ink or toner to buy, and the labels are already sticky, so you print, peel and stick. For anyone sending more than a handful of parcels a week, that’s quicker and tidier than printing on A4 and taping it on.

The trade-off is that direct thermal labels can fade over time with heat and sunlight. That doesn’t matter for a parcel that’s delivered in a few days, but they’re not ideal for labels that need to last for years.

Shipping labels are 4 × 6 inches, about 100 × 150 mm. UK sellers often call this 6×4, and it’s the same thing. This is the most important check.

Some small label printers are made for narrower labels, such as address or price labels, and can’t print a full-size shipping label. Look for a maximum print width of 4 inches (around 100 to 108 mm) in the specifications, not just the word “shipping”.

• USB: connects to a computer. Simple and reliable, but on its own it usually means printing from a Mac or PC, not your phone.
• Bluetooth: pairs with a phone or tablet, normally through the manufacturer’s app. Popular for printing from an iPhone at the kitchen table.
• Wi-Fi: joins your home network so several devices can use it. Some Wi-Fi printers support AirPrint.

Many printers offer more than one of these, so think about where you’ll usually be when you print.

This is where small sellers get caught out. There are two common setups:

• AirPrint support. The printer appears in the standard iOS print options. Check that it can print on 4×6 label stock this way, not just on its default paper.
• A manufacturer’s app. Many Bluetooth label printers only print through their own app. That’s fine, as long as the app can open PDFs shared to it from other apps, and lets you choose a 4×6 label size and print at 100%. Some apps only accept photos, which can make PDF labels less sharp.

Before you buy, read the app’s App Store listing and recent reviews, and look for mentions of PDF support and iPhone printing.

• Rolls or fanfold. Labels come on a roll or as a folded stack. Check which your printer takes and whether it has room for the size you want to buy.
• Third-party labels. Some printers work with any compatible direct thermal labels. Others need the maker’s own labels, sometimes with a chip. Compare the cost per label over a year, not just the printer price.
• Free labels. Some carriers offer free thermal labels to certain business account holders. Royal Mail mentions this for its Online Business Account customers, for example.

Most shipping label printers print at around 203 dots per inch, which is plenty for addresses and barcodes. Higher resolutions are nice to have, but not essential for parcels. Speed matters more if you print dozens of labels at a time. Think about desk space, too, and whether you’ll need to move the printer around.

1. Does it print the full 4×6 inch (100 × 150 mm) size?
2. Does it connect the way you’ll actually use it: USB, Bluetooth or Wi-Fi?
3. Can it print from an iPhone, through AirPrint or an app that accepts PDFs?
4. What do its labels cost, and can you use third-party ones?
5. Is there decent support and setup help for your device?

Even with the right printer, many labels arrive as A4 PDFs, screenshots or pages with instructions on them. Label Fixer crops the label to a portrait 4×6 PDF on your iPhone or iPad, ready to share to your printer’s app or save to Files. Our guide to cropping an A4 label to 4×6 shows how it works.