Enough that the dart does not slip, and no more: too little grip and the dart slides as you release, too much and it sticks to your fingers or wears your skin. Dry hands usually need more grip, as do players who throw hard. DartFit rates grip from 1 (smooth) to 5 (very grippy) and matches it to your preference.
What is knurling on a dart?
Knurling is the pattern cut into the barrel: rings, grooves, cross-hatching or fine micro-grip. Deeper and sharper cuts grip more. The cuts also remove metal, so a heavily machined barrel is a little lighter than a smooth one of the same size.
How do I know if I need more grip?
The dart slides forward in your fingers at release: more grip.
You squeeze harder than you would like to hold it: more grip.
The dart sticks or drags off your fingertips: less grip.
Your fingertips are sore after a session: less grip.
Does grip have to be the same along the barrel?
No. Many barrels have grip only where the fingers go and smooth sections elsewhere. If you hold the dart at the front, grip at the front matters most.
Frequently asked questions
Are smooth darts better?
Only if your fingers hold them without slipping. Most players like a medium grip; smooth suits a light, relaxed grip.
Do sweaty hands need more grip?
Often, yes; a dart grip wax or a slightly rougher barrel helps. Too sharp a barrel can still stick, so go one step at a time.