Label core size and winding direction explained
Roll won't fit, or the printer churns out blank labels? Nine times out of ten it's the core or the winding direction.
We all look at label size and price… and forget the two specs that decide whether the roll will work: core size and winding direction.
The core
The core is the cardboard tube in the middle of the roll. Its inner diameter has to match your printer's roll holder.
| Core | Where you'll find it |
|---|---|
| 25 mm (1 inch) | Small desktop printers |
| 40 mm (1.5 inch) | Desktop printers, everyday use |
| 76 mm (3 inch) | Industrial printers, large rolls |
Most desktop printers take 25 to 40 mm cores. Industrial printers usually use 76 mm cores with much bigger rolls.
Check the maximum roll diameter too: a roll that's too big stops the lid from closing.
Winding direction
- Wound out (outside wound): labels face the outside of the roll. Standard for desktop printers.
- Wound in (inside wound): labels face the core. Some printers and applicators need this.
If the winding is wrong, the printable side doesn't pass under the print head: the label comes out blank, or the adhesive sticks where it shouldn't.
Quick check: unroll a few centimetres. If the labels are on the outside of the strip, the roll is wound out.
What about automatic applicators?
On packing lines you also specify the unwind direction (top or bottom first, text left or right). Agree it with your label manufacturer.
Our rolls
Our thermal labels come on a 40 mm core, wound out, which suits the vast majority of desktop thermal printers. Need 76 mm cores, inside winding or a specific unwind direction for a machine? We make to order: get in touch through the wholesale page.
To choose the printer itself, read choosing a thermal label printer.
FAQ
Will a 40 mm core fit a printer made for 25 mm cores?
Often, yes. Desktop printer roll holders usually take 25 to 40 mm cores. Check your model's spec sheet.
Why are my labels coming out blank?
Usually the winding direction doesn't suit the printer, or you're using non-thermal labels without a ribbon.
Can you make rolls on 76 mm cores?
Yes, for business customers on request, with the winding direction you need.
