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Black nylon printer ribbon cartridge for Okidata ML420, 421, 490, 491

Innovera

Innovera AC-O0490 42377801 Printer Ribbon Black for Okidata ML420/421/490/491

SKU CH-5MNV-DP8TF MPN AC-O0490

Black nylon thermal-transfer ribbon compatible with Okidata ML420, ML421, ML490 and ML491 printers

  • CompatibilityOkidata ML420/421, ML490/ML491 printers
  • Type SpecificationsThermal Transfer
  • TypeRibbon
  • ColorBlack
  • Finish/SurfaceNylon
  • Selling UnitEach
  • Works with Okidata ML420, ML421, ML490, ML491 printers
  • Black nylon ribbon produces dark, sharp characters
  • Thermal-transfer technology gives consistent print quality
  • Long-life design reduces ribbon change frequency
  • Compatible replacement for OEM part 42377801

Compatible ribbon for Okidata ML series

The Innovera AC-O0490 is a black nylon printer ribbon built for Okidata Microline ML420, ML421, ML490 and ML491 models. It serves as a compatible replacement for OEM part 42377801. Offices and retail environments relying on these impact printers use it for continuous forms, invoices and multipart documents.

Thermal transfer operation and consumable nature

This ribbon uses thermal transfer technology to produce dark characters with sharp edge definition on every pass. Print density remains consistent until the ribbon is exhausted, at which point the entire cartridge is replaced. No separate ink supply or maintenance kit is required during normal use.

Drop-in fit for listed Microline and Pacemark models

The cartridge seats directly into the printer’s existing ribbon carriage without adapters or firmware updates. It frees the user from sourcing discontinued OEM stock while keeping the original print mechanism unchanged. Buyers needing colour output or laser-speed throughput will not be served by this impact consumable.

Highlights

  • Works with Okidata ML420, ML421, ML490, ML491 printers
  • Black nylon ribbon produces dark, sharp characters
  • Thermal-transfer technology gives consistent print quality
  • Long-life design reduces ribbon change frequency
  • Compatible replacement for OEM part 42377801

Specifications

BrandInnovera
ModelAC-O0490
CompatibilityOkidata ML420/421, ML490/ML491 printers
Type SpecificationsThermal Transfer
TypeRibbon
ColorBlack
Finish/SurfaceNylon
Selling UnitEach
Shipping weight0.45 kg
Package size127 × 76 × 25 mm

Questions about this item

How do I install the AC-O0490 ribbon in my Okidata ML420 and what step often gets missed?

Open the printer cover, remove the old cartridge, insert the new nylon ribbon until it clicks into both side notches, then manually turn the take-up knob clockwise to tension the ribbon before closing the cover — the tension step is the one most people skip.

What maintenance or replacement will the AC-O0490 need after extended printing on my ML491?

The ribbon is a single-use consumable; once the nylon fabric is exhausted and print fades, replace the entire cartridge — no separate ink refill or printhead service is required for this compatible ribbon.

What limit appears first during continuous high-volume printing with this ribbon on an ML421?

The finite length of the thermal-transfer nylon ribbon determines yield; when the roll fully unwinds the printer stops advancing ribbon, so output halts until a fresh cartridge is installed.

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