They must all be straight.
They must be the same length.
They must be round.
They must be made of the same material.
They must be fletched exactly the same.
They must balance at the same point.
They must be the same weight.
They must be the same in spine (stiffness).
In addition, they must be of the proper spine to match agiven bow weight.
Arrows of these matchings have all the guess work takenout of them; they will group in the same place on the targetif they are correctly loosed.
It is obvious that an archer cannot carry around with hima pair of accurate scales, a micrometer and a spine testerwhen he goes shopping for arrows. This is one time he willhave to recognize the old-fashioned word, faith. He will haveto depend on the reputation of the maker to furnish thesequalities in his products. Happily, there are such manufac-turers even in these times of mass production.