Inside Wound vs Outside Wound Ribbon — How to Tell and Why It Matters

Winding direction is which side of the ribbon faces outward on the roll. Outside wound has the ink on the outside; inside wound has it on the inner face. Most desktop printers take outside wound only, and some industrial printers take both. Check your printer manual, or a roll that already works, with the scratch test.

Thermal transfer ribbon is a thin film coated with ink on one side. 'Winding direction' describes which side of the film faces outward when the ribbon is wound into a roll.

Inside wound (IW): the ink-coated side faces inward, toward the core. The outer surface of the roll is the backing (non-ink) side.

Outside wound (OW): the ink-coated side faces outward. The outer surface of the roll is the ink side.

Why it matters: your printer's ribbon path is designed for one specific winding direction. Installing the wrong direction causes the ink to face away from the label — producing blank labels — or causes ribbon tracking issues and wrinkling.

Three ways to identify your printer's required winding direction:

1. Check your existing ribbon: look at a ribbon roll that works in your printer. The side of the ribbon you can scratch and leave a mark on is the ink side. Note whether this side faces in or out.
2. Check the printer manual or datasheet: most state the ribbon winding (ink side in or out) in the ribbon specification or loading section.
3. Check the ribbon path diagram inside your printer: most printers have a small diagram on the inside of the ribbon compartment cover showing the correct ribbon path.

For Zebra printers: desktop models (GK, GX, GC) take outside-wound ribbon only, and Zebra's FAQs point the ZD series to the same ribbons. The ZT230, ZT231 and 105SL Plus are outside only; the ZT410, ZT420, ZT610 and ZT620 take outside wound as standard, and inside wound only with Zebra's optional spindle. For TSC printers: desktop models (TE, TTP-244, TTP-247) take outside wound; the industrial MH and TTP-2410M models accept both. For Sato printers: the CL4NX Plus and CL6NX Plus accept both; the CT4-LX takes outside wound. For Honeywell printers: the PC42t takes outside wound only; the PM42 and PM43 accept both.

To test any ribbon roll:

1. Pull out 10cm of ribbon from the roll.
2. Fold the ribbon slightly and scratch the outer surface with your fingernail.
3. Does your nail leave a mark? If yes, the outer surface is the ink side → outside wound.
4. No mark on the outer surface? Scratch the inner surface (facing the core). If that leaves a mark → inside wound.

This test works for all ribbon grades — wax, wax-resin, resin, and wash-care.

Codewell Image labels all rolls clearly as 'IW' (inside wound) or 'OW' (outside wound) on the core. Specify your winding requirement when ordering and we'll ensure correct winding every time.

1. Zebra ZT231 user guide: Ribbon: the printer uses only ribbon coated on the outside, unless an optional spindle is fitted
2. Zebra ZT231 user guide: Performing an Adhesive Test and Performing a Ribbon Scratch Test: how to find the coated side
3. Zebra ZT231 user guide: Ribbon Issues: a ribbon coated on the wrong side cannot be used in the printer
4. Honeywell PC42t Desktop Printer User Guide: the PC42t can only use ribbon that is ink out