On some of my older Kydex lined Cordura sheathes the only point where there was any retention was on the 1/2" or so of the tip of the blade. When you were using the blade and slipped it back in the sheath it wasn't held very tightly allowing for easy withdrawal during repetitive cutting tasks and when you finally sunk it all the way in it held the blade securely. It only left a mark on the tip.