A fletching is used to stabilise the arrow.  Fletching an arrow with an angle, or offset, will force the arrow to spin during its flight, increasing stability.  But too much spin increases the drag and slows the arrow down, loosing speed and distance. 

There is no golden rule about what size fletching to use.  Generally speaking, the smaller the arrow the smaller the fletching, and vice-versa.  

The more finely tuned the bow, the less work the fletching needs to do to straighten the arrow. In fact, a super tuned bow can shoot an arrow without any fletchings surprisingly well. 

The type of bow you use also makes a difference.  For example, a compound archer using a release aid can use smaller fletchings as the arrow is launched with less flex and requires less correction.  But archers with a finger loose generate more arrow flex and can benefit from larger fletchings helping to stabilise the flight more quickly.   

By far, the most popular type of fletching.  Durable, easy to glue and low maintenance.  

The curled shape channels air-flow into the vane, forcing the shaft to spin, even when the arrow slows down. 

Feather fletchings are very forgiving and stabilise the arrow very quickly.  They have a built-in natural spin when fletched straight or are commonly fletched with a helical to increase spin and maximise arrow stability. 

They are often used on traditional bows that are shot from the shelf or hand, as feathers do not deflect in the same way as a plastic vane, but simply brush past.   

Although they are sold as ‘left wing’ and ‘right wing’, this does not reflect the hand of the archer but the wing of the bird.  A left handed archer can shoot a right wing feather perfectly well.  Just do not mix them!  Choose one or the other and you are all set. 

Pre-fletched onto a shrinkable tube, this is a quick and easy way to fletch arrows.  No glue required.  Only a cup of hot water!