Mark Two, our super durable, super compact pocket pen, ships with a mini version of the Schmidt 8126 rollerball refill. This is a fantastic refill, but if it's not your cup of tea, we've got you covered. We now make a simple adaptor that allows you to use any D1 style refill with Mark Two. Read below to see all our recommendations for D1 refills. Or just watch the video:
Refills for Mark Two come in three categories: rollerball, gel, and ballpoint. All three types are essentially the same mechanism: a ball in the tip that is coated in ink and rolled along the page. The difference between the three is how the ink is formulated.
Rollerball refills use a liquid ink that is a dye dissolved in water, similar to fountain pen inks. As such, the ink flows freely and requires very little pressure. But the paper choice is more critical because lower quality papers will exhibit feathering or bleed through.
Gel refills use an ink that consists of a pigment suspended in a water-based gel. They are known for a lubricated, smooth writing experience, but can sometimes skip more than rollerball or ballpoint, and the drying time is longer than ballpoints.
Ballpoint refills use an oil based ink, a mixture of dyes, alcohols and fatty acids. The ink is thick, so it works well on lower quality papers, but it requires the most pressure of the three to write. The lines are generally not as dark as rollerball or gel, but they are quick drying and waterproof.
The vast majority of D1 refills fall into the last category, ballpoint. Below are some refills that we have personally used and liked. All have been tested and confirmed to be compatible with Mark Two, with our D1 Adaptor.
One thing to keep in mind with D1 refills is, inherent in their small size, they hold quite a bit less ink than a normal refill. So expect to use them up faster than a traditional refill.
Schmidt 8126 Mini (Studio Neat)
This is the refill that is included with Mark Two. Lays down a smooth, dark line. As far as we know, this is the only rollerball refill that will fit in Mark Two.
Zebra JSB Gel (Jet Pens | Amazon)
There are very few gel refills in the D1 size, so if that is your preference, this is a good one to get. Available in two sizes (0.4 and 0.5 mm) and five colors options.
Uni Jetstream SXR-200 (Jet Pens | Amazon)
A ubiquitous and popular D1 refill choice. Available in 0.5 and 0.7 mm. I found the smaller one a bit scratchy, but the 0.7 is nice.
Zebra 4C (Jet Pens | Amazon)
Available in 0.4, 0.5, and 0.7 mm widths, making it the option with the finest tip. Again though, the smaller sizes are a bit rough on the page.
Pilot BRFS (Jet Pens | Amazon)
A really solid ballpoint option, smooth and vibrant. Available in 4 colors.
Monteverde Soft Roll (Jet Pens | Amazon)
Another really nice ballpoint, but best of all, it comes in 10 different color options.
Fisher SU4F Universal (Fisher | Amazon)
The classic pressurized space pen refill. This refill is sold in a longer form to fit various other pens, but you simply snap off the extra segments to get it down to a D1 size.
Kaweco D1 (Jet Pens | Amazon)
A reliable ballpoint option from a reputable brand.
Schmidt 635 Mini (Amazon)
Lays down a smooth, dark line, comparable to the Pilot and Monteverde.
OHTO R-4C7NP (Jet Pens | Amazon)
One of the few needlepoint D1 options, which gives the pen a cool look, almost like a mechanical pencil. Available in 0.5 and 0.7 sizes.
Here are all the lines side by side, for comparison:
We hope this guide is a useful primer for the world of D1 ink refills for Mark Two. As always, email us with any questions!