Zebra CJK-0.5 Gel Pen Refill 10-Pack – 0.5mm Japan | Black / Red Ink | Compatible with Zebra Sarasa Clip C-JJ6 & JJ15

Zebra CJK-0.5 Gel Pen Refill 10-Pack – 0.5mm Japan | Black / Red Ink | Compatible with Zebra Sarasa Clip C-JJ6 & JJ15

The right refill for the right pen. The Zebra CJK-0.5 gel ink refill is the genuine Japan-produced replacement cartridge for Zebra’s Sarasa Clip C-JJ6 range and other Zebra pens using the CJK cartridge format. Each refill contains Zebra’s water-based gel ink at a 0.5mm ball diameter — the standard fine-line specification for note-taking, exam writing, and everyday use that demands a clean, consistent ink line with minimal hand fatigue. Available in Black and Red, sold in a 10-pack for sustained supply without repeat ordering. Keep the pens you already use. Replace only the ink. The CJK-0.5 is the refill that makes Zebra’s gel pen body a long-term investment rather than a disposable product.

Same pen. Fresh ink. Keep writing.

✏️ Product Highlights

• Brand: Zebra (Japan)
• Model: CJK-0.5
• Pack: 10 refills of the same ink colour
• Tip size: 0.5mm ball — fine line, precise writing
• Ink type: Water-based gel ink — smooth flow, vivid colour, quick-drying on standard paper
• Ink colours available: Black / Red (select above)
• Primary compatibility: Zebra Sarasa Clip C-JJ6 (including the multi-colour rainbow barrel variants)
• Also compatible with: Other Zebra pens accepting the CJK cartridge format — see compatibility notes in the FAQ
• Origin: Japan

🇯🇵 Genuine Zebra Japan – Why the Origin Matters

Zebra’s gel ink formulation is produced to Japanese manufacturing standards — tighter quality tolerances for ink viscosity, ball-seat fit, and ink reserve volume than generic or third-party alternatives. The practical difference in daily use:

• Consistent flow: The ink starts on the first stroke without requiring priming or warming, and maintains consistent flow without skipping or blobbing across the full cartridge life.
• Accurate 0.5mm line: The ball diameter and seat are matched to Zebra’s specification — the 0.5mm line is reliably 0.5mm, not 0.6mm or varying. Consistent line width matters for note-taking legibility and exam answer formatting.
• No pen damage: Genuine Zebra refills are dimensionally identical to the original cartridge, ensuring correct seating in the tip mechanism without wear, misalignment, or leakage that can occur with incompatible third-party refills.

📝 0.5mm Gel Ink – The Note-Taking Standard

The 0.5mm ball diameter is the optimal specification for handwritten note-taking in the majority of contexts:

• Fine enough for small, dense handwriting on A4 or B5 ruled paper without the line width crowding the writing.
• Precise enough for exam answer booklets, official forms, and any writing where legibility under reduced-size reproduction is required.
• Gel ink advantage: At 0.5mm, gel ink produces a richer, more saturated line than ballpoint at the same width — more readable at a glance, requiring less writing pressure, and reducing hand fatigue in long writing sessions.

📦 What’s in the Box

• 10 × Zebra CJK-0.5 gel ink refills in your selected colour (Black or Red)
• Original Zebra Japan packaging

❓ Frequently Asked Questions

Q: Which Zebra pens is the CJK-0.5 refill compatible with?

A: The CJK-0.5 is the standard refill for Zebra Sarasa Clip C-JJ6 pens, including all barrel colour and multi-colour (rainbow) variants of the C-JJ6 range. It is also compatible with other Zebra pens that accept the CJK cartridge format, including the JJ15 Sarasa Clip and other Sarasa series models using the same cartridge standard. If you are unsure whether your specific Zebra pen accepts the CJK refill, check the pen barrel or the Zebra product page for the cartridge type listed.

Q: What is the difference between CJK-0.5, JK-0.5, and NJK-0.5?

A: These are Zebra’s refill format designations for different pen families:
CJK-0.5 — for Sarasa Clip C-JJ6 and compatible CJK-format pens (shorter cartridge).
JK-0.5 — for Sarasa Clip JJ15 and compatible JK-format pens (longer cartridge).
NJK-0.5 — for Sarasa Grand and other NJK-format pens (premium barrel series).
These formats are not interchangeable. Using the wrong refill format risks incorrect seating, leakage, or inability to fit. Check the refill format listed on your pen or its original refill packaging before purchasing.

Q: How many pages does each CJK-0.5 refill last?

A: Ink longevity depends on writing pressure, character size, and writing density. Under typical student note-taking conditions (standard-size handwriting, moderate pressure, A4 ruled paper), a single CJK-0.5 cartridge provides several weeks of regular daily use before running out. The 10-pack provides a supply sufficient for an extended school term for a single-pen user, or a shorter period for a multi-pen user who rotates colours frequently.

Q: Is the ink water-resistant once dry?

A: Zebra’s water-based gel ink has moderate water resistance once fully dry on standard paper — it does not smear or run immediately on contact with moisture after drying. It is not fully waterproof and should not be considered permanent ink. For applications requiring fully waterproof ink (e.g., labels, outdoor use, archival documents), a pigment-based ink pen is recommended.

Q: How do I install the CJK-0.5 refill in my Zebra Sarasa Clip?

A: To replace the refill in a Zebra Sarasa Clip C-JJ6: (1) Unscrew or pull apart the pen barrel at the grip section. (2) Remove the spent CJK refill cartridge by pulling it out of the tip. (3) Insert the new CJK-0.5 refill with the ball tip facing the pen nib end. (4) Reassemble the barrel and click the pen to extend the tip — the ink should flow immediately on the first stroke. No priming or break-in is required with a genuine Zebra refill.

Q: Does the red ink smear when highlighter is applied over it?

A: Zebra gel ink is quick-drying on standard paper and is resistant to smearing from most highlighters once the ink has dried (typically within a few seconds of writing). Oil-based highlighters pose no smear risk. Water-based highlighters may slightly affect the ink if applied immediately after writing before the ink has fully set. Allow a few seconds after writing before highlighting, and the ink will not smear under standard highlighter use.

Q: Can I use this refill in non-Zebra pens?

A: The CJK-0.5 cartridge is dimensioned for Zebra’s CJK-format barrel and tip mechanism. Some third-party pens with compatible cartridge dimensions may accept the CJK refill, but Zebra does not certify compatibility outside its own pen range. Using a Zebra refill in a non-Zebra pen may work in practice, but incorrect seating can cause leakage or performance inconsistency. For guaranteed performance, use the CJK-0.5 in the Zebra pens it is designed for.

Q: Why buy a 10-pack rather than individual refills?

A: A 10-pack provides a lower per-refill cost, fewer repeat orders, and an uninterrupted supply of ink for pens in regular daily use. For students who use a Sarasa Clip as their primary writing pen, running out of ink mid-exam or mid-lecture is a disruption a 10-pack prevents entirely. For users who rotate between black and red (e.g., annotation systems where red marks corrections and black writes main content), maintaining a 10-pack of each colour ensures neither colour runs out at an inconvenient time.