This substance is called G-10. It has multiple layers of laminated fiberglass that have been impregnated with epoxy resins. The result is a highly stable, durable material that is often used as a substrate for printed circuit boards.

This G-10 material is used for the caps, barrels, and grip sections. The surface has a checked pattern reminiscent of carbon fiber, but with a more subtle pattern. The color and pattern permeate the material, contributing to its depth of tone and durability. It is polished to a smooth semi-gloss finish. The tactile feel of the G-10 is warm and inviting to the hand. This the first use of this material that we know of for fountain pens. When the cap screws into the barrel, one can feel the texture of the G-10, a satisfying light resistance to the twist.