Not all tips are created equal...
Leather is the only natural fabric known to man. There are many unusual properties that are specific to leather which make it a highly desirable tip material. Leather is strong, shock resistant, adhesion friendly, and can be tanned to almost any degree of hardness. However, for the purpose of the game of pool, the most desirable characteristic of leather is its extremely slow impact recovery rate.
The finest leather is found on the shoulder and nape of the neck of the water buffalo. The hide found here is extremely thick and has less fat content, and the flesh side makes for a remarkably elastic membrane. This membrane acts as a shock absorber for the tip.
Each Black Boar tip is measured for how much and how quickly they compress. This process eliminates the vast majority of tips, as the most desirable tips fall within a very narrow range...and these are the only tips that ever find their way onto a cue. In a box of 50 tips, only 4-5 will typically make the cut.