Donau Ink Cartridges Blue 50 pcs — replacement refills for refillable pens

Donau Ink Cartridges Blue 50 pcs are a bulk pack of blue ink refills designed for compatible refillable pens. Each cartridge contains writing-grade blue ink suitable for everyday handwriting, note-taking and office documents. The pack provides a convenient supply for frequent users who need standard short ink cartridges for pen models that accept this cartridge size and format.

Advantages

The pack offers a large quantity of uniform blue cartridges that simplify restocking and reduce the need for frequent purchases. Cartridges are ready-to-install, minimizing downtime when replacing ink in refillable pens. The blue ink is formulated for clear, legible lines on common office and school paper types and dries quickly under normal conditions, reducing smudging during routine writing tasks.

Suitable for

• Everyday handwriting and note-taking
• Office forms and document signing
• Schoolwork and classroom use
• High-use environments requiring bulk ink supplies

Key specifications

• Color: blue
• Quantity: 50 cartridges per pack
• Compatible with refillable pens that accept standard short ink cartridges
• Intended use: writing on standard office and school paper

How to use

To replace a spent cartridge, open the pen according to the pen manufacturer’s instructions, remove the empty cartridge and insert a new Donau blue cartridge until it seats securely. Reassemble the pen and test on scrap paper to ensure ink flow. Store unused cartridges in a cool, dry place and avoid exposure to direct sunlight or extreme temperatures to preserve ink quality.

Usage recommendations

For best performance, use the cartridges with pens specified to accept short-format ink cartridges and allow a few seconds for fresh ink to start flowing after installation. If intermittent flow occurs after long storage, gently prime the tip on scrap paper.