Tomoe River paper is a silky smooth ultra thin paper (52 gsm) that performs great with fountain pens. The nib glides across the paper with hardly any feedback. The ink develops its full colour and sheens appear effortless.
There are other properties that make this paper special and highly coveted by fountain pen lovers such as:
No bleed-through
No feathering
So smooth
Thin and lightweight
Shows off ink characteristics shading and sheen (the foil-like effect that some inks have)