When you sheathe a dagger, once the animation is done your dagger has a somewhat weird hollow look.

Technically the textures seem to be drawn on the inside of the model instead of the outside. This is especially visible on the early-game daggers, not so much on fighting knifes and mercy-giver, due to their thin model mainly the lighting is wrong.

Generally daggers are a bit strange:
  • The punch dagger is far to large, its handle ought to fit in your fist, and it flips around when you sheathe it (pointing forward)
  • Same for the "rondel dagger" even for a rapier it's a bit too large.
  • Cutlery seems to be for masochists since golden daggers are held at the blade.