Hard Lessons Learned
Over the course of years of hunting wild boar with catchdogs, it became clear that making an impenetrable, or cut proof cut vest is impractical. Even if you did manage to accomplish it, it would be so bulky and cumbersome it would be useless the woods on an animal as fast and agile as a wild boar. Think a knight in a full suit of armor, vs. a gladiator in fighting armor. A knight in a full suit of plate armor was helpless on the ground in his bulky armor. On the other hand, a gladiator's armor still protected vitals and commonly hit areas, but left him fully mobile and agile. That's the concept we arrived at. Protect the vitals. Protect areas that take the most hits. Protect as much as you can, without sacrificing agility and movement.

Common Misconceptions
A good cut vest does not have to be "cut proof" to be effective. As mentioned above, no practical cut vest is cut PROOF, not even utilizing Kevlar and composite fabrics. Anyone who markets their vest as cut proof is  either misleading you, or has a vest that is not going to work in real world boar hunting. What a cut vest needs to do, is absorb about 80-90% of the damage that a boar's tusk inflicts. A cut vest should fool the boar into thinking he has a dog hooked on his tusks, and soak up most of the damage inflicted while the boar tries to rip the dog. On a light to medium cutting, the vest should absorb all the damage.  On a heavy cutting, what does get through should be no more than superficial or skin cuts. At the same time, the vest should allow the dog to move like it is not there and not significantly inhibit his range of motion. That's how a good cut vest works. In the ABSOLUTE  worst case scenario meaning the worst possible boar in the worst possible terrain, one of those one in a thousand nightmare scenarios where the advantage is all to the boar - a good cut vest should give the dog a fighting chance to make it out alive.

Examples
This vest, which was one of the original vests we developed and had made, sustained a severe cut right to the vitals. It cut through 2 layers of ballistic nylon, one layer of Cordura, and one layer of industrial felt. It did it's job perfectly. A direct hit in that area, of that magnitude on an unprotected dog probably would have resulted in serious injury or death. Instead it resulted in two skin staples and a scratch. At the same time, it allowed the dog wearing to move like he is in the picture on the bottom.  THAT is how a great cut vest is supposed to work. If the vest gets cut badly, but your dog doesn't, then that cut vest (or cut collar) did it's job!