Pentel Gel Pen CDT Energel Knock Red

The CDT EnerGel Knock is a collaboration between Craft Design Technology and Pentel – two Japanese brands that combine everyday writing instruments with design ambition. The matte plastic barrel features CDT's signature blackish-green, a hue deeply rooted in Japanese design history. Inside, Pentel's EnerGel refill in 0.5 mm delivers red ink: a gel refill whose exceptionally low viscosity ensures a fluid, almost resistance-free writing experience.

Features

• Low-viscosity EnerGel ink: The refill dispenses ink with lower viscosity than conventional gel ink – the result is a noticeably smoother line that penetrates paper quickly and dries within seconds. Smudging when your hand passes over the text becomes a thing of the past.
• Intense red: The EnerGel ink is heavily pigmented and appears rich and opaque on paper – not a pale, diluted red, but a clear, instantly legible statement. Ideal for corrections, highlighting and colour-coded note systems.
• Knock mechanism: Push button on the barrel, no cap needed – the refill is ready to use with one click and retracts just as quickly. In everyday use and meetings, this saves noticeable time.
• CDT barrel: The blackish-green plastic barrel is slightly more voluminous than the standard EnerGel, which allows for a more relaxed, less tense grip. Clip and end cap feature a metallic finish.
• Replaceable refill: The pen can be refilled with EnerGel refills – a durable alternative to single-use disposable pens.
• Not archival: EnerGel ink is water-sensitive and not archival-quality. Not suitable for documents requiring long-term preservation.

Use & Tips

• Daily notebook: On smooth, calendered paper, the EnerGel refill performs particularly cleanly – the line remains sharp without feathering. On lightly textured paper (70–90 g/m²) the fast drying time is most noticeable.
• Left-handed writers: Because of the very short drying time, the EnerGel is one of the few gel pens that writes reliably smudge-free for left-handers.
• Colour-coding & corrections: Red in 0.5 mm is precise enough for margin notes and corrections with tight line spacing – the line won't smudge before your hand reaches the next line.
• Planners & bullet journalling: The vibrant red makes deadlines, priorities or tracker columns stand out clearly – narrow enough for tight layouts, vivid enough to hold its own next to black ink.
• Refill replacement: EnerGel refills (0.5 mm, needle point) are simple to swap out. If you want a different colour in the same barrel, just replace the refill.

Technical Specifications