A6 Thermal Labels for AWBs: A Guide for Malaysian Sellers
Short answer: the sticker that Shopee, Lazada, TikTok Shop and the courier portals print the airway bill on is a 100 x 150 mm direct thermal label, sold in Malaysia as A6. It has no ink: the printer’s head heats a coating on the paper and the heated spots turn black, so the label roll is the only running cost. That same coating is why labels print blank when the roll goes in upside down, fade in a hot van or a sunny storeroom, and go grey when they meet hand sanitiser. This guide covers the size, the roll, the five printing problems that account for nearly every complaint, how to store rolls in our climate, and how to put a label on a once-used carton so the courier scans the right barcode. The labels are on the shop under thermal label stickers, by the roll or by the carton.
What “A6” means on a label roll
Paper A6 is 105 x 148 mm, a quarter of an A4 sheet. The label on your parcels is not quite that. The airway bill document that the marketplace seller centres and the courier portals generate is laid out for a 100 x 150 mm label, the 4 x 6 inch shipping label used by couriers around the world, and that is the size on the roll. The trade in Malaysia calls both “A6” because they are close enough that a 4-inch label printer handles either, and because “A6” is what the print dialogue in Seller Centre says. The number that matters is the 100 mm width: a desktop label printer has a print head around 104 mm wide, so a 100 mm label is the widest it prints edge to edge, and a 105 mm sheet would lose a strip.
If you are still printing the A6 PDF onto A4 paper, cutting it out and taping it on, a thermal label does the same job in one pass with no ink, no scissors and no tape over the barcode. Shopee’s own seller guidance recommends a thermal printer for airway bills because inkjet print smudges and the scanner then fails on the barcode.
Direct thermal, and why there is no ink
A direct thermal label is paper with a heat-sensitive coating on the face. The print head is a row of tiny heaters. Where a heater fires, the coating turns black; where it does not, the label stays white. Nothing is transferred onto the paper, which is why there is no cartridge, no toner and no ribbon to buy, and why the only thing you ever replace is the roll.
The other kind of label printing is thermal transfer, where the same kind of head melts ink off a ribbon onto a plain or synthetic label. Thermal transfer print does not fade in heat or light and survives a year on a shelf, which is why product barcodes and asset labels use it. It costs a ribbon and a ribbon-capable printer, which an airway bill does not need. A parcel label has to survive a few days in a courier network, not a year in a warehouse, so direct thermal is the right tool, and the cheap 4-inch printers that Malaysian sellers buy are nearly all direct thermal only.
Two things follow from the coating:
- The coated face must touch the head. On a roll, the labels are wound with the coated face outward. Load the roll so the labels come off the top and pass under the head face up; the quick start card for your printer shows the path. Loaded the other way, the printer heats the backing paper and prints nothing.
- Anything that heats the label prints on it. Sunlight, a hot dashboard, a lorry parked at noon, a hair dryer, a hot shoplot ceiling in a storeroom. The coating does not know the difference between the print head and the afternoon sun.
Roll or fanfold, and will it fit the printer
Thermal labels come two ways in Malaysia: on a roll wound around a cardboard core, and as fanfold, a flat zig-zag stack with a perforation between labels. A roll sits inside a desktop printer or on an external holder behind it; a fanfold stack sits behind the printer and feeds through the slot in its back. Fanfold holds more labels in one stack and lies flat, which some sellers prefer; a roll feeds with steadier tension and takes up less bench space, which is why most desktop printers are designed around one. Our range is rolls.
Before ordering a carton, check two numbers against your printer manual:
| Printer spec | What it limits | Where to find it |
|---|---|---|
| Core size | The hole in the middle of the roll has to fit the spindle. Common cores are 25 and 40 mm. | Printer manual; measure your current roll’s core |
| Maximum roll diameter | A roll fatter than the printer’s bay will not close inside it; a holder behind solves it. | Printer manual, often around 100 to 127 mm |
| Label width | The guides inside the printer set to the label width. | 100 mm for this label |
| Gap or black mark | The sensor finds the start of each label by the gap in the backing or a printed mark. | Gap labels are the usual kind |
If the core on our roll does not match your spindle, a desktop printer usually has an adapter in the box, and an external holder takes any core. Our product page lists what is known about the roll; for anything it does not state, such as the exact core or the label count per roll, ask us before buying the carton. The single roll exists for exactly this trial.
The five problems that account for nearly every complaint
| What you see | Most likely cause | Fix |
|---|---|---|
| Blank label | Roll loaded upside down; thermal transfer stock; wrong paper size in driver | Scratch test, reload face up, set 100 x 150 mm in the driver |
| Grey, faint or patchy print | Darkness too low; speed too high; dirty head; damp or old labels | Raise darkness one step at a time, slow the print, clean the head with an alcohol wipe when cold, open a fresh roll |
| Label prints half, or two labels feed per job | Printer has lost the label gap | Run the printer’s calibration (hold the feed button as the manual says) so the sensor relearns the gap |
| Barcode will not scan | Faint print; barcode over a fold or curve; tape or film over the barcode | Fix the print; put the label on a flat face, not over a seam; never tape over the barcode; keep it out of a flyer’s pocket |
| Label small and off-centre, or cut off | Document scaled to fit, or printing from a browser preview | Print at 100 per cent or “actual size”, choose the 100 x 150 mm paper size, print from the downloaded PDF |
Three of the five come from the portal rather than the printer. Every seller centre and courier portal has a document format setting, usually a choice between A4 and A6 or between a normal and a thermal layout. Set it once to A6 or thermal and the airway bill arrives laid out for the label. Then print at actual size, not “fit to page”: the barcode has to come out at the size the courier’s scanner expects, and a shrunk barcode with thin bars is the first thing a handheld scanner refuses.
The darkness setting is the one to understand. Higher darkness means more heat, which prints blacker but wears the head faster and can fill in the white gaps in a barcode until the scanner cannot tell the bars apart. Start from the printer’s default, go up one step only if the print is faint, and if you have to go up more than a step or two, the real problem is usually a dirty head or a damp roll.
Our climate: storing rolls and labelled parcels
Thermal labels are a paper product with a heat-sensitive face, so they have both problems our post on cartons going soft in humidity describes, plus one of their own.
- Heat darkens the coating. A roll stored under a shoplot roof, next to a window or on top of the printer’s power brick slowly goes grey before it is ever printed, and the print on it comes out with less contrast. Suppliers commonly put the shelf life of an unprinted roll at one to two years in cool, dry storage; a hot storeroom shortens that. Keep rolls in their carton in the air-conditioned part of the shop, not in the store at the back.
- Humidity curls the paper. A roll that has taken up moisture feeds badly, loses its gap calibration and prints lighter because the damp face takes more heat to darken. Keep the carton closed, take out one roll at a time, and use the oldest roll first.
- Sun fades the print. A printed label in direct sun can fade in weeks, which does not matter for a parcel that is delivered in two days, but matters for a parcel that waits on a porch, in a hot car boot or on a sunny collection counter. Keep sealed parcels in the shade until the courier takes them.
- Solvents and oils grey the print. Hand sanitiser, oil from a packing bench, and plasticised PVC such as some clear pouches react with the coating. Dry hands, a clean bench, and the label stuck on the parcel rather than slipped into a plastic sleeve.
- Rubbing greys it too. The coating darkens under friction, which is why a label that has been dragged across a bench or stacked under other parcels comes out with a grey smear. Stack labelled parcels label-side up.
For anything that has to stay readable for a year, a shelf label, a stock bin, an asset tag, direct thermal is the wrong tool, whatever the storage. That is thermal transfer’s job.
Putting the label on a once-used carton
Reusing a carton saves about half the cost of a new one and keeps the board in use, and our once-used Grade A cartons are checked, clean and unprinted on at least one face for that reason. The label step is where a reused box goes wrong, and it is the same step whether the box came from us or from the back of a mini market.
- Kill every old barcode. A courier’s handheld scanner reads the first barcode it finds. An old airway bill, a manufacturer’s carton barcode or a previous marketplace label left on the box can be scanned instead of yours and send the parcel to the wrong hub. Peel what peels, and cross out the rest with a thick marker until no bar is readable, or cover it with a plain label.
- Pick a flat, clean face. Not the lid flaps, where the join under the tape moves; not a face with a crease or a dent, where the label bridges a hollow and the barcode bends. Wipe the dust off, because thermal label adhesive holds poorly on dusty brown board.
- Press from the centre out. Lay the label down flat and rub it from the middle to the edges so there is no bubble across the barcode.
- Nothing over the barcode. Not tape, not film, not the flyer’s pocket. Our flyer bag guide explains why the pocket is for the invoice and the label goes on the flat face of the bag. The one exception is a parcel going out in the rain, where a strip of clear tape at the edges of the label, clear of the bars, keeps it on.
- Then the photo. Our fragile-parcel post for online sellers explains why a picture of the sealed parcel with the airway bill readable is what wins a damage dispute. Take it after the label is on, while the print is fresh.
Tape over the seams and the barcode uncovered is the rule for the whole parcel. Our tape post covers the H-seal and why tape fails on a dusty box; the parcel size limits post covers what the courier will take once it is labelled.
Roll or carton
Buy one roll first. It goes through the printer, you learn the core, the diameter, how the roll sits and what darkness setting suits it, and you find out whether your printer is happy with it before there are twenty-three more rolls on the shelf. After that, the carton of 24 is the cheaper way to buy per roll, and the carton is also the right place to store the spares: closed, dark and dry, with one roll out at a time. A seller at a few orders a day gets through a roll slowly enough that a carton is many months of labels, so the storage advice above matters more for the carton than for the single roll.
Checklist
- Portal set to A6 or thermal format, printed at actual size from the downloaded PDF
- Driver paper size 100 x 150 mm, darkness at default or one step up
- Roll loaded face up, guides set to the label, calibration run after every new roll
- Scratch test on any roll that prints blank
- Head cleaned with an alcohol wipe when it is cold, every few rolls
- Rolls in the carton, air-conditioned, oldest first
- Old barcodes crossed out on every reused carton
- Label on a flat clean face, pressed from the centre, nothing over the barcode
- Labelled parcels stacked label-up, in the shade, until collection
FAQ
Is an A6 thermal label the same as a 100 x 150 mm label?
In the courier and marketplace trade, yes. Paper A6 is 105 x 148 mm, but the label that Shopee, Lazada, TikTok Shop and the courier portals lay their airway bill out for is 100 x 150 mm, the 4 x 6 inch shipping label, and that is what sellers and suppliers in Malaysia call A6. A 4-inch desktop label printer has a print head about 104 mm wide, so 100 mm is the widest label it prints edge to edge.
Why does my thermal printer print blank labels?
Three causes cover most cases. The roll is loaded the wrong way round, so the heat-sensitive face is not against the print head. The labels are thermal transfer stock, which needs a ribbon that a direct thermal printer does not have. Or the printer is printing a blank page because the document is scaled or the paper size in the driver does not match the label. Scratch the label with a fingernail or a coin first. Direct thermal stock leaves a dark mark; if nothing appears, the label is the wrong type.
Why do thermal labels fade, and how long do they last?
A direct thermal label has no ink. A heat-sensitive coating turns dark where the print head heats it, and anything that heats the label again, including sunlight, a hot van or a hot storeroom, slowly darkens the background and greys the print. Oils, hand sanitiser and plasticised PVC do the same by contact. Guides commonly give an unprinted roll one to two years in cool, dry storage and a printed label months to years indoors, but only weeks in direct sun. For a parcel delivered in a few days that is fine. For a label that has to stay readable for a year, use thermal transfer.
Do I need special labels for a once-used carton?
No, the same label works, but the box needs preparing. A once-used carton often carries its previous barcode, and a courier scanner can read the old one instead of yours. Cross out or cover every old barcode and address, pick a flat unprinted face, wipe the dust off, and press the new label on from the centre outwards. Never put the label over a seam, a flap edge or the tape, and never put clear tape over the barcode.
Should I buy a single roll or a carton of thermal labels?
Start with one roll. Rolls differ in core size, outer diameter and face, and a roll that does not fit your printer’s holder or feeds badly is a problem you want to find at one roll, not twenty-four. Once a roll has run through your printer cleanly, the carton is the cheaper way to buy, and it keeps the spare rolls boxed and out of the light until you need them.
Where to get it
The A6 100 x 150 mm direct thermal label is on the shop under thermal label stickers as a single roll or a carton of 24 rolls, with current prices on the product page, next to flyer bags with a pocket, packing tape and cutters and once-used Grade A cartons from RM1.10. Delivery across KL and Selangor is free on orders of RM300 and above, and a flat RM30 per trip below that.
Setting up a packing bench, or not sure whether the roll fits your printer? WhatsApp +60 16-891 6381 or contact us with the printer model and your daily order count, and we will tell you what we know about the roll and put together the labels, bags and boxes to match. We are open Monday to Friday 8.30am–5pm and Saturday 8.30am–1pm, and closed on Sundays and public holidays.