TWSBI Diamond Mini Fountain Pen - Black / ClearA more grounded Diamond Mini The TWSBI Diamond Mini Black takes the transparent mechanical appeal of the Diamond series and frames it with black accents for a more focused, understated look. The clear barrel keeps the ink and piston system visible, while the black cap and grip reduce visual noise and give the pen a more controlled presence. Built around TWSBIs reliable piston filling system and fitted with a smooth stainless steel nib, this is a