Smooth vs rough grip

[Shirasaya]

does anyone here use a katana with a smooth hardwood tsuka? I am just asking because i have used a Tai Chi straightsword with a smooth handle and found it to be comfortable. Katana tend to be two-handed weapons, is a rough handle preferable only for 2 handed weapons in your experience? The wrapped same and cotton tsuka is certainly preferable if one values authenticity and tradition, but what advantage does it have?

[chidokan]

if you examine most swords from around the world you will find some kind of binding on most grips. Some go further and add a wrist loop to prevent dropping it. The main reason is that a smooth surface is slippy when wet and is easier to drop, so in combat with sweat, blood, possibly rain around, you need a good rough surface.