Schmidt Technology has been developing and producing ballpoint refills in Germany for more than half a century, and that depth of experience shows the moment the tip meets paper.
The 635 is the company's D1 format mini refill, a format trusted by some of the most respected names in writing instruments worldwide. When pen manufacturers at this level choose a refill to put inside their products, they choose Schmidt.
The Writing Experience
The 635 is fitted with a high-quality stainless steel tip and a tungsten carbide ball, which together deliver the kind of controlled, consistent line that ballpoint enthusiasts will recognise immediately.
The medium 0.7mm tip produces a clean, defined stroke in a deep, true black. There is no skipping, no dry starts, no inconsistency across the page. It simply writes, every time.
The ink flow is smooth without being wet, which means you get crisp letterforms without the smearing that can plague lesser ballpoint refills. Whether you are signing documents, journaling, or jotting notes at pace, the 635 keeps up without fuss.
Compatibility
This is where the 635 earns its reputation as the workhorse of the D1 world. It fits any pen that accepts the international D1 mini ballpoint refill format, which covers an impressively broad range of instruments across every price point. Compatible pens include the Kaweco Sport and Liliput, Lamy multi-pens, Rotring multi-pens (Duo, Trio, and Quattro), Retro 51 Tornado Elite and Touch, Parker Executive Quattro, and the Monteverde Tool Pen, among many others.
If your pen takes a D1 refill, this is almost certainly the one to reach for.
Specifications
Why It Matters
A fine pen deserves a refill that honours it. Slipping a poorly made refill into a Kaweco or a Rotring is a false economy - you feel the difference immediately. The Schmidt 635 maintains the integrity of the writing experience your pen was designed to deliver. It is not the cheapest D1 refill on the market, but it is consistently one of the best, and for anyone who writes regularly, that distinction matters.
Pre-order item
Soft armchair
$420.00
Select variant
Select purchase option
