Our pens were designed to be used with an International Standard converter but they can also can be used with International Standard or International Short cartridges.

Be sure to manually push the cartridge into the grip section to successfully puncture the cartridge.

DISCLAIMER: As with any fountain pen that was not specifically designed to be an eyedropper pen, the user makes this conversion at their own risk.

That said, our 100% resin pens can be. Any other material, like wood, cannot be. In our tests we used both silicone grease and a rubber o-ring (1mm thick, 7mm inside diameter, 9mm outside diameter) to get the best seal possible.

For our testing we used Lamy Blue/Black ink. It did not stain, though we did not do a long-term test.

Most standard, water-based inks should not stain the resin. However, some highly saturated or pigmented inks may tint or stain the pen, particularly the lighter-colored resins. When in doubt, look it up—there are likely posts and reviews online regarding the specific ink you are wondering about.

We use Alumilite urethane resin, which is made in Kalamazoo, Michigan.

The small batch nature of our pens doesn’t mean we won’t make more of a colorway. Feel free to reach out and ask us about the specific colorway.

Yes. Please email us at info@redbranchcrafts.com for a consultation.