Six materials
We work in a narrow range, on purpose. Each material here behaves in a specific way, and every product page says which of these it is made from.
Brass
C360 free-machining brass, turned on a lathe and left unlacquered. It tarnishes within weeks and darkens over years; that is the finish, not a defect. Polishes back with any brass polish.
Aluminum
6061 alloy, hard-anodized after machining. About half the weight of brass at the same size. The anodized layer resists scratches but shows them as bright metal if one gets through.
Resin
Cast acrylic, turned from rod rather than injection-molded. Light in the hand at 22 g, warm to the touch, and dents rather than cracks when dropped.
Steel
Stainless steel nibs with a hard alloy tip, tuned before they ship. Spring-steel clips. Neither rusts in a pocket or a bag.
Leather
Vegetable-tanned full-grain, 2 mm, saddle-stitched with waxed linen thread. Darkens and softens with handling; rain marks it.
Paper
90 gsm, sized for fountain pen ink so a medium nib dries in about 15 seconds without feathering. Some ghosting with broad nibs; no bleed.