Arrow Fletching:

Glued near the rear of most arrows are 3 (sometimes 4) feathers or plastic vanes, arranged in an equal pattern around the circumference of the shaft.  These parabolic-shaped pieces of material (sometimes collectively called the "fletching") serve to help steer the arrow during flight.  If the tail of the arrow is precisely following the tip during flight, the fletching slices cleanly through the air without changing the arrow's path.  But if the arrow's tail isn't perfectly following the tip, friction occurs between the air and the fast moving fletch - pushing the fletch (and the tail of the arrow) back into proper alignment with the arrow's tip.  So the fletching helps to stabilize and correct the arrow's flight.  Easy enough!

Of course, all fletching materials aren't created equal either.  Arrow fletching is available in a number of different shapes, colors, types, thicknesses, lengths, etc.  And they can be applied in different configurations:  straight, offset, or helical (spiral).  So how do we know which ones to pick?  Should we go with feathers?  Or vanes?  Would a bigger fletch do a better job than small ones?  Is one more durable than another? What are the trade-offs?  Well, let's start with the easy ones.

 Feathers or Vanes?

Vanes are made of soft flexible plastic and are the popular choice for today's archer.  They're inexpensive, easy to apply, quiet in flight, available in almost any size/color, and they can be easily fletched in a number of different patterns (straight - offset - helical).  Since vanes are impervious to water, they make an excellent all-weather choice for hunting.  In addition, they're also relatively durable.  Vanes can be crumpled and abused (up to a point of course) and they still pop back into shape - not nearly as delicate as feathers.  However, compared to feathers of the same size, vanes are quite heavy - as much as 3X the weight of a comparable feather.  And since vanes have a smooth surface area, they don't "dig-into" the air as well as the rougher surface of feathers.  So all other things being equal, vanes don't stabilize arrow flight quite as well as feathers.
 
But feathers have their ups and downs too.  Firstly, feathers are rather expensive.  Basic 4" feathers can cost up to 4X as much as comparable vanes.  Feathers that are barred, or have intricate patterns/designs, or feathers that have specialized shapes can be as much as 10X the cost of standard vanes.  And feathers must generally be fletched in a helical (spiral) configuration.  Since feathers aren't flexible enough to be manipulated easily like vanes, they usually come pre-formed in either a right spiral (called right-wing) or left spiral (left-wing).  Feathers typically cannot be fletched in a straight or offset pattern.  And of course, feathers don't hold up well to weather or rough-handling.  BUT, many archers swear by feathers for good reason.  Feathers are very light.  Three 4" Gateway feathers weigh just over 8 grains - compared to 24 grains for three 4" Duravanes.  This means your arrows fly faster with less loss of trajectory downrange.  And when it comes to design, you just can't deny that mother nature knows best.  Feathers do a tremendous job at stabilizing arrow flight - but they're not for everyone or every application. 

Think you know which one is best for you?  Well hold on just a moment.  This is an important decision.  There are a few other factors you should consider before you jump to your conclusion about feathers vs. vanes. 

 Straight - Offset - Helical?

Another factor that determines the effectiveness of your fletching is the TURN of the fletch.  If your fletching is arranged in a helical (spiral) pattern - like a boat propeller - your arrow will rotate in flight.  Much like a football that's thrown with a perfect spiral, an arrow will fly straighter and be more stable if it rotates in-flight.  Aerodynamically, a helical configuration is clearly a better choice.  However, a helical fletch may not always be appropriate or necessary for your particular bow setup.  For example, some arrow rests will not provide enough clearance to allow a helical fletch to pass thru without contact.  In this case, many archers use an offset fletch, where the vanes are still straight, rather than in a spiral pattern, but they are slightly turned on the shaft to promote some rotation in-flight without compromising fletching clearance.  For very unforgiving arrow rests with limited clearance, or for competition target setups that don't require much stabilization, the straight fletch may be the best option.  Take a look at the diagrams below and the corresponding pro's and con's associated with each fletching configuration.  When you order your arrows, you'll need to select one of these options. 

Right or Left?

If you choose to go with an offset or helical fletch, the arrow will rotate in flight.  But which way should it rotate?  Right or left?  Feathers, which come in right-wing and left-wing shapes, can make the arrow rotate either direction depending upon your choice.  And vanes can be fletched right or left as well. 

An arrow with a right turn will rotate clockwise (as viewed from the nock) during flight.  An arrow with a left turn will rotate counterclockwise.  So what's the big difference?  With most modern setups........nothing.  One is as good as the other.  The only major difference is that left-turn (counterclockwise) arrows tend to impact the target and loosen your tips, while right-turn (clockwise) arrows tend to impact the target and tighten your tips.  Otherwise, it really makes no difference.

Of course, this wasn't always the case.  The traditional wisdom is for RH shooters to shoot a right turn fletch and LH shooters to shoot a left turn fletch.  And if you shoot a traditional bow OR you have an old-fashioned flipper or plunger style rest, this is still good advice for achieving the best vane/feather clearance.  But for shooters with modern equipment and center-shot cutaway risers, if you have to pick one or the other, we suggest you choose a right turn.  Or you can flip a coin.  :)

Fletching Size:  How Big to Go?
Most vanes and feathers are available in several different sizes.  The most common are the 3", 4", and 5", with the 4" being the industry standard for most applications.  However, you may decide a little larger or smaller fletch is better for you, but there are a few things to consider.

Weight:  If you're concerned about your finished arrow weight or your F.O.C. balance (more on this in a moment), it's worth noting that your choice and size of fletching material will have a significant impact on both of those attributes.  Take a look at the chart below to see how much your fletching choice will add to your finished arrow.  Since all of that weight is going to be concentrated in the rear of the arrow, heavy fletching material means a you'll also need more tip weight to maintain a good F.O.C. balance.
 

Surface Area:  In addition to the TURN of your fletching, the second factor that determines how much stabilization you can expect will be directly related to the total amount of surface area of the fletching material you select.  Larger fletching will have more surface area, small fletching will have less.  The more surface area, the more resistance the fletching will have with the surrounding air and the more effective the fletching will be at correcting the arrow in flight.  Compare the total surface area (both sides) of the standard 3", 4" and 5" fletch.
 

Three 5" vanes will have over twice the surface area of three 3" vanes.  So a 5" fletch would arguably be better for stabilizing the arrow, right?  Perhaps.  Just remember that archery is all about trade-offs.  If you go with a huge fletch, you'll also have more weight, less FOC, and the larger fletchings may or may not clear your arrow rest properly.  A heavy load of vanes also decreases your arrow spine (though only slightly).   

Fletching Choice:  Recommendations

First and foremost, your fletching choice should be what yields the best accuracy.  So before you choose your fletching type, it's important to consider how difficult your arrows will be to stabilize in flight.  If you only use your bow for recreational target shooting with field points or target nibbs, a 3" fletch will probably be sufficient.  Field points are easy to stabilize.  But broadheads are another story.  If you shoot broadheads (particularly large fixed-blade broadheads) which often tend to fly erratically, a larger fletch will be essential to achieving good arrow flight and consistent groups.  If you shoot mechanical broadheads, you can get by with a little less.  There probably isn't a true right and wrong here, as fletching material is essentially a personal choice.  But here is general chart to help you select a reasonable fletching option for your setup.